In the last 50 years the media influence has grown exponentially with the advance of technology, first there was the telegraph, then the radio, the newspaper, magazines, television and now the internet. We live in a society that depends on information and communication to keep moving in the right direction and do our daily activities like work, entertainment, health care, education, personal relationships, traveling and anything else that we have to do. A common person in the city usually wakes up checks the tv news or newspaper, goes to work, makes a few phone calls, eats with their family when possible and makes his decisions based on the information that he has either from their co workers, news, tv, friends, family, financial reports, etc.
What we need to be aware is that most of our decisions, beliefs and values are based on what we know for a fact, our assumptions and our own experience. In our work we usually know what we have to do based on our experience and studies, however on our daily lives we rely on the media to get the current news and facts about what is important and what we should be aware of. We have put our trust on the media as an authority to give us news, entertainment and education. However, the influence of mass media on our kids, teenagers and society is so big that we should know how it really works.
Of all the media distribution channels the most influential has been the television, we are constantly exposed to thousands of images of violence, advertising, sex, celebrities and much more, in fact a its known that a child is exposed to about 40,000 ads a year. Years ago there was more diversity in companies, but they have merged so now they are just a few and they have the power to shape the opinion and beliefs of us and our kids. So its important to be aware of what your kids are exposed to every day and you should also try to look at things from different perspectives and not just from the one the media gives you.
The media makes billions of dollars with the advertising they sell and that we are exposed to. We buy what we are told to be good, after seeing thousands of advertisings we make our buying decisions based on what we saw on Tv, newspapers or magazines to be a product we can trust and also based on what everyone else that we know is buying and their decision are also base don the media. These are the effects of mass media in teenagers, they buy what they see on Tv, what their favorite celebrity advertise and what is acceptable by society based on the fashion that the media has imposed them.
Wednesday, March 4, 2009
Media Influences on Violence
Television executives are also quick to deny the influence of media violence. Yet the entire economy of television hinges on viewers' suggestibility. When NBC sells time to Microsoft and Toyota, it does so by hawking the tube's power to move minds. (The fact that individual commercials may fail to result in purchases is immaterial here.) Media's ability to influence people is a no-brainer for the simple fact that media is everywhere and everything; it is central to American culture. To argue that people aren't influenced by media is to argue that they aren't influenced by culture, and you don't need to be Margaret Mead to know that's insane.
When Fonzie brandished a library card on Happy Days library registration shot up nationwide. After a popular Budweiser campaign, people began greeting their pals, "Whassupp!" (To capitalize on the spots' popularity with children, J. C. Penney even sold "Whassup" kiddie T-shirts.) When Ally McBeal wore a certain style of pajamas, thousands of viewers asked retailers for them. It's the same thing with movies. ET and Reese's. Tom Cruise and Ray-Bans. Dirty Harry and . 44 Magnums. And it's not just companies that exploit media's influence. Many large nonprofit groups--from the NAACP to the White House drug office to the American Medical Association--hire people to lobby Hollywood for favorable coverage.
Does violence in the media influence the real world? Of course it does. Cop shows and crime reports make us scared of other people, of going out at night, of helping out strangers. That is perhaps its primary effect. But there should be no doubt that watching violence can also lead to violence. To say that it can is not to say that it does in most circumstances, with most people, in most places. Nor is it to say that violent media creates violent behavior out of nowhere. Whether someone's violent tendencies originated with an abusive parent or with Dirty Harry is on a certain level irrelevant; the fact remains that a steady diet of media blood and guts isn't good for some people, some of the time.
To say all this is simply to acknowledge an uncomfortable truth, one for which there is no easy solution. Censorship by righteous experts or government officials is not the answer. Even if you ignore the serious First Amendment issues involved, censorship schemes could at best treat only the symptoms. The real problem with the media is not overt violence, but an unchecked market that churns out content strictly for bucks. The only solutions, then, are far more radical: the establishment of a truly public broadcasting system, as opposed to the limp vessels of PBS and NPR. Let the corporate-owned networks program whatever garbage they like. Providing true alternatives to commercial media would give viewers more choices. And even if a fraction of the audience watches the alternative channels, their presence would help put things in perspective, onscreen and off.
When Fonzie brandished a library card on Happy Days library registration shot up nationwide. After a popular Budweiser campaign, people began greeting their pals, "Whassupp!" (To capitalize on the spots' popularity with children, J. C. Penney even sold "Whassup" kiddie T-shirts.) When Ally McBeal wore a certain style of pajamas, thousands of viewers asked retailers for them. It's the same thing with movies. ET and Reese's. Tom Cruise and Ray-Bans. Dirty Harry and . 44 Magnums. And it's not just companies that exploit media's influence. Many large nonprofit groups--from the NAACP to the White House drug office to the American Medical Association--hire people to lobby Hollywood for favorable coverage.
Does violence in the media influence the real world? Of course it does. Cop shows and crime reports make us scared of other people, of going out at night, of helping out strangers. That is perhaps its primary effect. But there should be no doubt that watching violence can also lead to violence. To say that it can is not to say that it does in most circumstances, with most people, in most places. Nor is it to say that violent media creates violent behavior out of nowhere. Whether someone's violent tendencies originated with an abusive parent or with Dirty Harry is on a certain level irrelevant; the fact remains that a steady diet of media blood and guts isn't good for some people, some of the time.
To say all this is simply to acknowledge an uncomfortable truth, one for which there is no easy solution. Censorship by righteous experts or government officials is not the answer. Even if you ignore the serious First Amendment issues involved, censorship schemes could at best treat only the symptoms. The real problem with the media is not overt violence, but an unchecked market that churns out content strictly for bucks. The only solutions, then, are far more radical: the establishment of a truly public broadcasting system, as opposed to the limp vessels of PBS and NPR. Let the corporate-owned networks program whatever garbage they like. Providing true alternatives to commercial media would give viewers more choices. And even if a fraction of the audience watches the alternative channels, their presence would help put things in perspective, onscreen and off.
Children abuse by Media
Life on many television shows and movies is far from normal. They often glamorize potentially destructive behaviors like drinking, drugs, affairs, and intimate teen relationships. As a parent you can counteract the media's influence by pointing out how the actions of the people on screen are potentially dangerous. Alcohol commercials never show the hangovers the next day. Rarely does a teenage girl get pregnant or someone contract a sexually transmitted disease in the media. Research done by both RAND and the University of North Carolina also shows that teenagers who are exposed to more sex talk and acts in the media are more likely to engage in those same behaviors themselves.
Dr. Brown, one of the researchers says, "Teens are defaulting to entertainment media for sexual information because they aren't getting this information in other places. Unfortunately, the media aren't the best sex educators. The media tend to leave out the crucial three C's: commitment, contraception and consequences." The study on media influence on children also pointed out that parents could have a greater impact on their teen's sexual behavior than the media when they talk about it. Taking the time to discuss the things that our children view in the media will ensure that they are learning the things that we want them to and not the lessons that the media might be teaching thus avoiding negative influence of media.
Life on many television shows and movies is far from normal. They often glamorize potentially destructive behaviors like drinking, drugs, affairs, and intimate teen relationships. As a parent you can counteract the media's influence by pointing out how the actions of the people on screen are potentially dangerous. Alcohol commercials never show the hangovers the next day. Rarely does a teenage girl get pregnant or someone contract a sexually transmitted disease in the media. The majority of child abuse cases stem from situations and conditions that are entirely preventable in an engaged and supportive community.
A community that cares about early childhood development, parent support and maternal mental health, for instance, is more likely to see families nurturing children who are born healthy and enter school ready to learn. Cities and towns that work to create good school systems and who come together to ensure that affordable housing is available in good, safe neighborhoods are less likely to see stressed, isolated families who don't know where to turn. Child Abuse Prevention Month is about connecting all of these dots so that the solutions to child abuse receive the attention the public craves.
Dr. Brown, one of the researchers says, "Teens are defaulting to entertainment media for sexual information because they aren't getting this information in other places. Unfortunately, the media aren't the best sex educators. The media tend to leave out the crucial three C's: commitment, contraception and consequences." The study on media influence on children also pointed out that parents could have a greater impact on their teen's sexual behavior than the media when they talk about it. Taking the time to discuss the things that our children view in the media will ensure that they are learning the things that we want them to and not the lessons that the media might be teaching thus avoiding negative influence of media.
Life on many television shows and movies is far from normal. They often glamorize potentially destructive behaviors like drinking, drugs, affairs, and intimate teen relationships. As a parent you can counteract the media's influence by pointing out how the actions of the people on screen are potentially dangerous. Alcohol commercials never show the hangovers the next day. Rarely does a teenage girl get pregnant or someone contract a sexually transmitted disease in the media. The majority of child abuse cases stem from situations and conditions that are entirely preventable in an engaged and supportive community.
A community that cares about early childhood development, parent support and maternal mental health, for instance, is more likely to see families nurturing children who are born healthy and enter school ready to learn. Cities and towns that work to create good school systems and who come together to ensure that affordable housing is available in good, safe neighborhoods are less likely to see stressed, isolated families who don't know where to turn. Child Abuse Prevention Month is about connecting all of these dots so that the solutions to child abuse receive the attention the public craves.
Bad Influence of Media on Children
At an early age books, movies, television, and the Internet influence how our children think and act in a variety of ways. As children grow these media influences become even more powerful. The media influences on children is not always a good influence and parents need to counteract this influence by discussing and monitoring what their children are exposed to. The media often stereotypes people and races. Most children's programming deals in absolutes reinforcing the idea that people are good or bad, stupid or smart and because of their inexperience children will latch onto stereotypes that they see.
Parents can counteract this stereotyping by commenting when a group is portrayed inaccurately. Let your children know for example that every blond isn't stupid, and wearing black doesn't make you a bad guy. Point out that everyone has good and bad traits. So, often in the media a character is either good or bad, but in real life this is not the case. The media uses its influence on children to market items and influence your child's desires making them think that they need certain items to be popular or cool.
My children often comment on things that they saw in commercials. The other day my son told me that I should get a kitchen chopper, because it can cut things up so much faster than I can using a knife. I replied that I don't need a kitchen chopper because a knife works just fine. Every year children influence their parents spending by convincing them to buy things that the media has portrayed as "cool". Children recognize name-brand products at an early age because they see them in the media. My children recognized the McDonalds sign by age three even though we never eat there, because they saw commercials on television.
Counteract the marketing by pointing out the faulty logic in commercials. Ask your child if they really think having the latest toy will make them more popular or happy. Children often don't realize that a Barbie won't move around like it does on the commercials or that the elaborate set doesn't come with the toy. Parents can teach their children that things do not equal happiness. Try rewarding with praise and time instead of objects. My children know that they don't get what they see on television and they rarely ask.
Parents can counteract this stereotyping by commenting when a group is portrayed inaccurately. Let your children know for example that every blond isn't stupid, and wearing black doesn't make you a bad guy. Point out that everyone has good and bad traits. So, often in the media a character is either good or bad, but in real life this is not the case. The media uses its influence on children to market items and influence your child's desires making them think that they need certain items to be popular or cool.
My children often comment on things that they saw in commercials. The other day my son told me that I should get a kitchen chopper, because it can cut things up so much faster than I can using a knife. I replied that I don't need a kitchen chopper because a knife works just fine. Every year children influence their parents spending by convincing them to buy things that the media has portrayed as "cool". Children recognize name-brand products at an early age because they see them in the media. My children recognized the McDonalds sign by age three even though we never eat there, because they saw commercials on television.
Counteract the marketing by pointing out the faulty logic in commercials. Ask your child if they really think having the latest toy will make them more popular or happy. Children often don't realize that a Barbie won't move around like it does on the commercials or that the elaborate set doesn't come with the toy. Parents can teach their children that things do not equal happiness. Try rewarding with praise and time instead of objects. My children know that they don't get what they see on television and they rarely ask.
Consumerism
We are all susceptible to the messages we see in the media, but the influence of media on children is particularly powerful. Many of our basic beliefs are formed in our early years and media can hold sway if not monitored and regulated by parents. Per Wikipedia, consumerism is the "equating of personal happiness with the purchasing of material possessions and consumption." Nearly all forms of media are filled with both overt and subliminal messages encouraging us to buy. Academic experts have attributed depression, anxiety, and other emotional maladies with consumerism.
It is said by some to be leading us to a social/financial catastrophy, and certainly even religious leaders have seriously challenged the value of our consumer based culture. Reports have indicated that many families in the US have their TV on an average of 6 ¾ hours per day potentially giving their TV a stronger foothold in a child's education than their school teacher. According to The Sourcebook for Teaching Science, the average child in fact, views 1500 hours of television per year compared to spending only 900 hours per year in school.
With so much time to educate and entertain, it becomes clear that television is indeed a powerful force in how we perceive things; both for adults and for children. Certainly for advertisers, children are a desirable target as they are even less likely to be consciously aware that those who promote products are attempting to shape they way they think and behave. There are a number of ways parents can exert some control over the influence of media on children. With younger children it isn't too complicated to limit their exposure to television and other types of media.
However, it becomes increasingly important for parents to take an active role in how kids evaluate what they see in print, on television, and on the internet. With media advertising often targeting children specifically, it is important for parents to learn what they can about the techniques used by ad companies. The resources below will help. Parents can then engage their kids in looking critically at the marketing that is thrown at them in an effort to thwart the influence of media on children. Several of the links below will discuss the types of questions parents can use when talking to their children about these topics.
It is said by some to be leading us to a social/financial catastrophy, and certainly even religious leaders have seriously challenged the value of our consumer based culture. Reports have indicated that many families in the US have their TV on an average of 6 ¾ hours per day potentially giving their TV a stronger foothold in a child's education than their school teacher. According to The Sourcebook for Teaching Science, the average child in fact, views 1500 hours of television per year compared to spending only 900 hours per year in school.
With so much time to educate and entertain, it becomes clear that television is indeed a powerful force in how we perceive things; both for adults and for children. Certainly for advertisers, children are a desirable target as they are even less likely to be consciously aware that those who promote products are attempting to shape they way they think and behave. There are a number of ways parents can exert some control over the influence of media on children. With younger children it isn't too complicated to limit their exposure to television and other types of media.
However, it becomes increasingly important for parents to take an active role in how kids evaluate what they see in print, on television, and on the internet. With media advertising often targeting children specifically, it is important for parents to learn what they can about the techniques used by ad companies. The resources below will help. Parents can then engage their kids in looking critically at the marketing that is thrown at them in an effort to thwart the influence of media on children. Several of the links below will discuss the types of questions parents can use when talking to their children about these topics.
Media and its influences
Television can be a powerful entertainment and education tool for children given the right programming. However, studies have shown that television, and media in general, can also have a very negative influence. Some studies indicate it can shorten attention span, distort body image, work in conjunction with other factors to escalate obesity, create fear, and increase agressive and anti-social behaviors if exposure is unmonitored and unlimited. Learn about what the research shows regarding the influence of media on children.
The dangers, and how to counteract the potential negative influence here on this page as we cover what parents need to know. The influence of media on children extends to health related issues. Although television has the power to educate on nutrition, exercise, and a wide variety of health related issues, it can also be a negative force through images and advertisements which influence viewers to make poor food choices or to overeat. In addition, excessive television viewing can result in inactivity which further contributes to excessive weight gain and poor fitness levels.
Children are specifically targeted by some advertisements and are even more vulnerable than adults to their influence. Adults must assist children in questioning and thinking critically about the messages they see on TV. Limiting television viewing time and encouraging physical activity are precautions that parents should consider. The influence of media on children also extends into how we view ourselves and others. Television shows portray women in a certain way. Generally focusing primarily on their attractiveness; or at least Hollywood's version of it.
These images from movies, television, and all kinds of advertisements bombard women; often with the effect of creating an unattainable image in their minds of how they should appear. Anorexia, bulemia, low self-esteem and a host of other problems can result. These images of course, can also effect the expectations that men have regarding how women "should" behave and look. Talking with young girls about the images they see and giving them better role models can be important.
Wetlands
Through the ages, urban wetlands have been the lifeline of most cities in India. They were preserved and looked after by the people as their main source of water supply for drinking and irrigation. These wetlands are found all over the country and are either natural or built by people. Over the years, they have gradually depleted, leading to a number of problems in urban areas such as flooding, water scarcity, and water logging. Tanks were constructed in the catchment areas of cities that were not located near a river or a large lake.
Rainwater or run-off would collect during the monsoons and be stored for the rest of the year in these tanks and lakes. The city would get its water supply from these. In southern India, the towns were built around a temple, which always had a tank at the centre. Wells were located in the tank, which served as a link with the aquifers. There were innumerable tanks dug by the rulers, most of which have been destroyed. In fact, in some areas tank building by the ruler was considered a noble deed. In Karnataka, the Hoysalas built tanks all over the state.
Some of these still exist. Festivals were organized around tanks; cleaning and de-silting the tanks were a part of the rituals. But over the years, human activity steadily destroyed these wetlands. In Bangalore, the city bus terminus has been built on the Dharmambudhi tank. A part of the Sampangi tank has given way to the Kanteerva stadium and the remaining to a housing colony. Another lake was filled up to house the city market. Once upon a time, these urban wetlands maintained a steady supply of water for the city, recharged the groundwater, cooled the city, and prevented flood as they were a natural drainage system.
Over the years, these very tanks and wetlands have been neglected, encroached upon either to accommodate more houses or to dump waste. This has caused large-scale water crisis and monsoon flooding and water logging, leading to misery and disease. These wetlands that have been protected for centuries are now being ravaged and destroyed in the name of development. People in the urban areas must learn to live in harmony with nature in their own habitat. The wetlands, the green belts, and the flora and fauna of these areas have to be preserved for urban areas to survive and remain healthy.
Rainwater or run-off would collect during the monsoons and be stored for the rest of the year in these tanks and lakes. The city would get its water supply from these. In southern India, the towns were built around a temple, which always had a tank at the centre. Wells were located in the tank, which served as a link with the aquifers. There were innumerable tanks dug by the rulers, most of which have been destroyed. In fact, in some areas tank building by the ruler was considered a noble deed. In Karnataka, the Hoysalas built tanks all over the state.
Some of these still exist. Festivals were organized around tanks; cleaning and de-silting the tanks were a part of the rituals. But over the years, human activity steadily destroyed these wetlands. In Bangalore, the city bus terminus has been built on the Dharmambudhi tank. A part of the Sampangi tank has given way to the Kanteerva stadium and the remaining to a housing colony. Another lake was filled up to house the city market. Once upon a time, these urban wetlands maintained a steady supply of water for the city, recharged the groundwater, cooled the city, and prevented flood as they were a natural drainage system.
Over the years, these very tanks and wetlands have been neglected, encroached upon either to accommodate more houses or to dump waste. This has caused large-scale water crisis and monsoon flooding and water logging, leading to misery and disease. These wetlands that have been protected for centuries are now being ravaged and destroyed in the name of development. People in the urban areas must learn to live in harmony with nature in their own habitat. The wetlands, the green belts, and the flora and fauna of these areas have to be preserved for urban areas to survive and remain healthy.
Other Indian Lakes
Deepor Beel : This is a permanent freshwater lake, in a former channel of the Brahmaputra river, south-west of Guwahati city. It is a large natural wetland having great biological and environmental importance and is also the only major storm water storage basin for Guwahati. The beel is endowed with rich floral and faunal diversity. In addition to a huge congregation of residential water birds, the Deepor ecosystem harbours a large number of migratory waterfowl each year. It is now threatened with large scale encroachment, brick making factory and soil cutting within the beel ecosystem, and construction of railway line along the southern boundary of the beel.
The Hussain Sagar Lake: This is one of the largest man-made lakes in Asia, located in the heart of Hyderabad, contributing to its immense beauty. It is a sprawling artificial lake that holds water perennially. It was built during the reign of Ibrahim Qutub Shah in 1562, on a tributary of the river Musi. The Tso Morari Lake : This is one of the largest in the Ladakh region and is almost like an inland sea. Situated at an elevation of about 4,900m, it is about 22km long, with a width varying from 5 to 7km and a depth of more than 30 m at the deepest point.
The lake is probably a leftover from the Ice Age, formed by the melt waters of the ice masses left behind by the retreating glaciers. The waters from the surrounding areas drained into the lake. The huge amounts of water present in the beginning evaporated very fast in the desert-like atmosphere and what was fresh water became brackish and finally salty, unfit for human consumption. One of the most spectacular lakes in Ladakh is the Pangong Tso, which lies across the Changla Pass from Leh.
At an altitude of almost 4,500 metres, the Pangong Tso is only 8 km wide at its broadest point, but is an amazing 134km long. The Pangong is considered to be the longest lake in Ladakh. It is a saltwater lake formed in much the same way as the Tso Morari lake during the Ice Age. There is considerable uncertainty about defining the difference between lakes and ponds. For example, limnologists have defined lakes as waterbodies which are simply a larger version of a pond or which have wave action on the shoreline, or where wind induced turbulence plays a major role in mixing the water column. None of these definitions completely excludes ponds and all are difficult to measure.
The Hussain Sagar Lake: This is one of the largest man-made lakes in Asia, located in the heart of Hyderabad, contributing to its immense beauty. It is a sprawling artificial lake that holds water perennially. It was built during the reign of Ibrahim Qutub Shah in 1562, on a tributary of the river Musi. The Tso Morari Lake : This is one of the largest in the Ladakh region and is almost like an inland sea. Situated at an elevation of about 4,900m, it is about 22km long, with a width varying from 5 to 7km and a depth of more than 30 m at the deepest point.
The lake is probably a leftover from the Ice Age, formed by the melt waters of the ice masses left behind by the retreating glaciers. The waters from the surrounding areas drained into the lake. The huge amounts of water present in the beginning evaporated very fast in the desert-like atmosphere and what was fresh water became brackish and finally salty, unfit for human consumption. One of the most spectacular lakes in Ladakh is the Pangong Tso, which lies across the Changla Pass from Leh.
At an altitude of almost 4,500 metres, the Pangong Tso is only 8 km wide at its broadest point, but is an amazing 134km long. The Pangong is considered to be the longest lake in Ladakh. It is a saltwater lake formed in much the same way as the Tso Morari lake during the Ice Age. There is considerable uncertainty about defining the difference between lakes and ponds. For example, limnologists have defined lakes as waterbodies which are simply a larger version of a pond or which have wave action on the shoreline, or where wind induced turbulence plays a major role in mixing the water column. None of these definitions completely excludes ponds and all are difficult to measure.
Indian Lakes
Keoladeo National Park: This is an important habitat for waterfowl. It is the only wintering site in India for the central and western Asian population of Siberian cranes, a highly endangered species. The population of Siberian Cranes has decreased in the last two decades. In a programme now underway, reared Siberian crane chicks are being brought to Keoladeo from USA and Siberia. Loktak Lake. The measures undertaken for the conservation of Loktak Lake so far, include afforestation of indigenous species including fruit trees; control of silt; catchment area treatment; removal of floating lands locally called phumdis in some pockets of the lake; and generating awareness about the values and functions of the wetland.
Several measures have been adopted to control the prolific growth of phumdis and water hyacinth. Weevils have been introduced for biological control of water hyacinth.Harike Lake: This wetland sustains a large number of waterfowl. Demarcation of the wetland has been attempted, and fencing has been carried out of some ponds. Afforestation of catchment area has been carried out in some critical areas to control siltation. One of the major problems faced by this wetland is the prolific growth of water hyacinth.
Wular Lake: This wetland is the source of drinking water for Srinagar, and also acts as an absorption basin for floodwater. It is an important waterfowl habitat. However, Wular Lake is subject to heavy siltation due to loss of vegetal cover in the surrounding area. Sambhar Lake: Located in the arid zone of Rajasthan, the Sambhar Lake is one of the largest inland saline lakes in India. This wetland is one of the most important wintering areas for flamingoes and pelicans. Salt extraction is one of the major activities in the wetland.
The Bhoj Wetland in Bhopal, Madhya Pradesh : It consists of two man-made lakes (upper and lower lakes). The upper lake was created in the 11th century by constructing an earthen dam across the Kolans river and the lower lake was constructed nearly two centuries ago. The wetland supports a wide variety of flora and fauna. Diverse flora provide ideal habitat for a large number of avifauna. Biotic interaction and natural selection have led to the development of a characteristic relationship between vegetation and the avifauna.
Several measures have been adopted to control the prolific growth of phumdis and water hyacinth. Weevils have been introduced for biological control of water hyacinth.Harike Lake: This wetland sustains a large number of waterfowl. Demarcation of the wetland has been attempted, and fencing has been carried out of some ponds. Afforestation of catchment area has been carried out in some critical areas to control siltation. One of the major problems faced by this wetland is the prolific growth of water hyacinth.
Wular Lake: This wetland is the source of drinking water for Srinagar, and also acts as an absorption basin for floodwater. It is an important waterfowl habitat. However, Wular Lake is subject to heavy siltation due to loss of vegetal cover in the surrounding area. Sambhar Lake: Located in the arid zone of Rajasthan, the Sambhar Lake is one of the largest inland saline lakes in India. This wetland is one of the most important wintering areas for flamingoes and pelicans. Salt extraction is one of the major activities in the wetland.
The Bhoj Wetland in Bhopal, Madhya Pradesh : It consists of two man-made lakes (upper and lower lakes). The upper lake was created in the 11th century by constructing an earthen dam across the Kolans river and the lower lake was constructed nearly two centuries ago. The wetland supports a wide variety of flora and fauna. Diverse flora provide ideal habitat for a large number of avifauna. Biotic interaction and natural selection have led to the development of a characteristic relationship between vegetation and the avifauna.
Lakes
A lake is a low-lying part of the Earth's surface in which rainwater, surface water run-off, outflow from a river, and water from other sources accumulates. There is a great variety of lakes on Earth: there are freshwater lakes and saltwater lakes, ranging in size from small fish-ponds to huge waterbodies such as Lake Superior in USA which is the world's largest freshwater lake. The Caspian Sea in Europe and the Sambhar lake in Rajasthan are examples of saltwater lakes. India has a large number of lakes spread all over the country, from Kashmir to Kerala and from Rajasthan to Assam.
Among the better-known fresh water lakes in India are the Dal lake in Srinagar and the Nainital lake. Whether natural or manmade, all lakes are major sources of water. Lakes are homes to a large variety of aquatic life, with one notable exception: the Dead Sea, a saltwater lake in Israel does not have any form of life. There is too much salt in its water to sustain life. Almost half of the world's lakes are degraded, depleted, and contaminated mainly by human activities. The main causes are inflow of domestic sewage, agricultural run-off, discharge of industrial effluents, over-fishing, introduction of exotic species and habitat degradation from population growth, expansion of cities.
As more water is withdrawn for human use and more of it is returned to lakes and rivers badly polluted there is less available to maintain vital freshwater ecosystems. The deepest lake is Lake Baikal in Siberia, Russia. The deepest point of the lake is known as the Olkhon Crevice; it has a depth of 5,370 feet. The largest saline lake is the Caspian Sea, spread over parts of Iran, Russia, Turkmenistan, Azerbaijan, and Kazakhstan with a surface area of 1 43 560 square miles and an estimated volume of 21 500 cubic miles. The most threatened lake in terms of size is the Aral Sea, which has shrunk due to extraction of water for irrigation.
Natural lakes on Earth are generally found in mountainous areas, rift zones, and areas with ongoing or recent glaciation. Other lakes are found in endorheic basins or along the courses of mature rivers. In some parts of the world, there are many lakes because of chaotic drainage patterns left over from the last Ice Age. All lakes are temporary over geologic time scales, as they will slowly fill in with sediments or spill out of the basin containing them.
Among the better-known fresh water lakes in India are the Dal lake in Srinagar and the Nainital lake. Whether natural or manmade, all lakes are major sources of water. Lakes are homes to a large variety of aquatic life, with one notable exception: the Dead Sea, a saltwater lake in Israel does not have any form of life. There is too much salt in its water to sustain life. Almost half of the world's lakes are degraded, depleted, and contaminated mainly by human activities. The main causes are inflow of domestic sewage, agricultural run-off, discharge of industrial effluents, over-fishing, introduction of exotic species and habitat degradation from population growth, expansion of cities.
As more water is withdrawn for human use and more of it is returned to lakes and rivers badly polluted there is less available to maintain vital freshwater ecosystems. The deepest lake is Lake Baikal in Siberia, Russia. The deepest point of the lake is known as the Olkhon Crevice; it has a depth of 5,370 feet. The largest saline lake is the Caspian Sea, spread over parts of Iran, Russia, Turkmenistan, Azerbaijan, and Kazakhstan with a surface area of 1 43 560 square miles and an estimated volume of 21 500 cubic miles. The most threatened lake in terms of size is the Aral Sea, which has shrunk due to extraction of water for irrigation.
Natural lakes on Earth are generally found in mountainous areas, rift zones, and areas with ongoing or recent glaciation. Other lakes are found in endorheic basins or along the courses of mature rivers. In some parts of the world, there are many lakes because of chaotic drainage patterns left over from the last Ice Age. All lakes are temporary over geologic time scales, as they will slowly fill in with sediments or spill out of the basin containing them.
Prevention of Ground water Contamination
It is important to realize that groundwater is not a resource that could be utilized unmindfully simply because it is available in abundant quantities. Problems and issues such as water logging, salinity, agricultural toxins, and industrial effluents, all need to be properly looked into. Other than legislation and checks to conserve and improve the quality of groundwater, society itself plays a very important role. During the last decade there has been a rising awareness among the common people on the need for conservation and development of groundwater.
Water use has to be integrated effectively with water regeneration, as was done in many traditional technologies. Renovation of forest tanks in drought-prone regions will have a significant impact on wildlife and forest cover. Similarly, in some urban cities there is a need to regenerate groundwater aquifers because of the high degree of dependence on them for drinking water. Rainwater harvesting schemes have been taken up in many cities and even made compulsory in some of them. Temple tanks need to be renovated and urban wetlands protected. All these will contribute to a rise in the groundwater level and a reduction of salt water ingress. Community awareness and management of freshwater resources should be enhanced.
The government should implement effective groundwater legislation and regulations through self-regulation by communities and local institutions. External support agencies should support freshwater resource management. Environmental restoration should be promoted along with household water security.No single action whether community based, legislation, traditional water harvesting systems, or reliance on market forces will in itself alleviate the crisis in India. The effective answer to the freshwater crisis is to integrate conservation and development activities – from water extraction to water management – at the local level; making communities aware and involving them fully is therefore critical for success.
All this will ultimately pave the way for combining conservation of the environment with the basic needs of people. In India, the Water (Prevention and Control) Act was passed by the Parliament in 1974, and by 1990 all the states adopted the act. In 1986, the Environment Protection Act was passed by the Parliament. Under both these acts, the states and the central government developed environmental norms for air emissions and waste water discharge for different types of sources.
Water use has to be integrated effectively with water regeneration, as was done in many traditional technologies. Renovation of forest tanks in drought-prone regions will have a significant impact on wildlife and forest cover. Similarly, in some urban cities there is a need to regenerate groundwater aquifers because of the high degree of dependence on them for drinking water. Rainwater harvesting schemes have been taken up in many cities and even made compulsory in some of them. Temple tanks need to be renovated and urban wetlands protected. All these will contribute to a rise in the groundwater level and a reduction of salt water ingress. Community awareness and management of freshwater resources should be enhanced.
The government should implement effective groundwater legislation and regulations through self-regulation by communities and local institutions. External support agencies should support freshwater resource management. Environmental restoration should be promoted along with household water security.No single action whether community based, legislation, traditional water harvesting systems, or reliance on market forces will in itself alleviate the crisis in India. The effective answer to the freshwater crisis is to integrate conservation and development activities – from water extraction to water management – at the local level; making communities aware and involving them fully is therefore critical for success.
All this will ultimately pave the way for combining conservation of the environment with the basic needs of people. In India, the Water (Prevention and Control) Act was passed by the Parliament in 1974, and by 1990 all the states adopted the act. In 1986, the Environment Protection Act was passed by the Parliament. Under both these acts, the states and the central government developed environmental norms for air emissions and waste water discharge for different types of sources.
Ground Water Contamination
Groundwater is an integral part of the environment, and hence cannot be looked upon in isolation. There has been a lack of adequate attention to water conservation, efficiency in water use, water re-use, groundwater recharge, and ecosystem sustainability. An uncontrolled use of the borewell technology has led to the extraction of groundwater at such a high rate that often recharge is not sufficient. The causes of low water availability in many regions are also directly linked to the reducing forest cover and soil degradation. Pollution of groundwater resources has become a major problem today.
The pollution of air, water, and land has an affect on the pollution and contamination of groundwater. The solid, liquid, and the gaseous waste that is generated, if not treated properly, results in pollution of the environment; this affects groundwater too due to the hydraulic connectivity in the hydrological cycle. For example, when the air is polluted, rainfall will settle many pollutants on the ground, which can then seep into and contaminate the groundwater resources.
Water extraction without proper recharge and leaching of pollutants from pesticides and fertilizers into the aquifers has polluted groundwater supplies. In addition, leachates from agriculture, industrial waste, and the municipal solid waste have also polluted surface- and ground-water. Some 45 million people the world over are affected by water pollution marked by excess fluoride, arsenic, iron, or the ingress of salt water. As far as the quality of groundwater is concerned, many states in the country have been identified as endemic to fluorosis due to abundance in naturally occurring fluoride-bearing minerals.
These are Andhra Pradesh, Gujarat, Haryana, Orissa, Punjab, Rajasthan, Tamil. The situation is aggravated by the problem of water pollution or contamination. India is heading towards a freshwater crisis mainly due to improper management of water resources and environmental degradation, which has lead to a lack of access to safe water supply to millions of people. It gives special attention to drinking water for both humans and animals over its other uses. The policy calls for controls on the exploitation of groundwater through regulation and an integrated and coordinated development of surface- and ground-water.
What is Ground Water
The importance of groundwater for the existence of human society cannot be overemphasized. Groundwater is the major source of drinking water in both urban and rural India. Besides, it is an important source of water for the agricultural and the industrial sector. Water utilization projections for 2000 put the groundwater usage at about 50%. Being an important and integral part of the hydrological cycle, its availability depends on the rainfall and recharge conditions. Till recently it had been considered a dependable source of uncontaminated water.
The demand for water has increased over the years and this has led to water scarcity in many parts of the world. The situation is aggravated by the problem of water pollution or contamination. India is heading towards a freshwater crisis mainly due to improper management of water resources and environmental degradation, which has lead to a lack of access to safe water supply to millions of people. This freshwater crisis is already evident in many parts of India, varying in scale and intensity depending mainly on the time of the year.
Groundwater crisis is not the result of natural factors; it has been caused by human actions. During the past two decades, the water level in several parts of the country has been falling rapidly due to an increase in extraction. The number of wells drilled for irrigation of both food and cash crops have rapidly and indiscriminately increased. India's rapidly rising population and changing lifestyles has also increased the domestic need for water. The water requirement for the industry also shows an overall increase. Intense competition among users — agriculture, industry, and domestic sectors — is driving the groundwater table lower.
The quality of groundwater is getting severely affected because of the widespread pollution of surface water. Besides, discharge of untreated waste water through bores and leachate from unscientific disposal of solid wastes also contaminates groundwater, thereby reducing the quality of fresh water resources. As far as the quality of groundwater is concerned, many states in the country have been identified as endemic to fluorosis due to abundance in naturally occurring fluoride-bearing minerals. These are Andhra Pradesh, Gujarat, Haryana, Orissa, Punjab, Rajasthan, Tamil.
Glaciers
Glaciers are large sheets of ice that flow down very high mountains and are often the source of snow-fed rivers. Glaciers, found mainly in places such as Antarctica and Greenland, cover almost 10% of the earth's landmass, varying in size. A glacier begins life as snowflakes. As more snow falls and gathers, the weight of the snow on top compresses the lower layers to form ice. The pile of snow and ice becomes thicker and heavier till the point when the layer of ice at the very bottom melts under the pressure.
It re-freezes almost at once; but the process is repeated over and over, and as a result the entire mass begins to slide downhill slowly along the rock surface. A glacier has an enormous impact on the topography of the area, pushing aside boulders, cutting through rocks, and denting its path as it moves. Most of the world's glaciers are found at the Poles, but they exist on all of the world's continents, even Africa. Australia doesn't have any glaciers; however, it is considered part of Oceania, which includes several Pacific island chains and the large islands of Papua New Guinea and New Zealand. Both of these islands have glaciers.
Glaciers require very specific geographical and climatic conditions. Most are found in regions of high snowfall in winter and cool temperatures in summer. The amount of precipitation (whether in the form of snowfall, freezing rain, avalanches, or wind-drifted snow) is important to glacier survival. In areas such as Siberia and parts of Antarctica, the lack of adequate precipitation prevents glacier development. Dokriyani: This glacier is believed to be as old as the Himalayan Mountains. Dokriani 'Bamak' is a well-developed medium sized glacier of the Bhagirathi basin.
The glacier is 5 km long and flows in a northwest direction terminating at an elevation of 3,800 m. It originates at an altitude of 13 000 feet in Uttaranchal's Garhwal district. It is one of the most studied glaciers in the world. A recent study says that it has been shrinking by a few metres every year. Gangotri: This is located in Uttaranchal's Tehri Garhwal. One of the oldest glaciers in the Chaukhamba range, it is where the river Ganga originates. The Gangotri is not a single valley glacier, but a combination of several other glaciers that are fed to it and form a huge mass of ice. The glacier covers 28km and terminates at Gaumukh (4,000m).
It re-freezes almost at once; but the process is repeated over and over, and as a result the entire mass begins to slide downhill slowly along the rock surface. A glacier has an enormous impact on the topography of the area, pushing aside boulders, cutting through rocks, and denting its path as it moves. Most of the world's glaciers are found at the Poles, but they exist on all of the world's continents, even Africa. Australia doesn't have any glaciers; however, it is considered part of Oceania, which includes several Pacific island chains and the large islands of Papua New Guinea and New Zealand. Both of these islands have glaciers.
Glaciers require very specific geographical and climatic conditions. Most are found in regions of high snowfall in winter and cool temperatures in summer. The amount of precipitation (whether in the form of snowfall, freezing rain, avalanches, or wind-drifted snow) is important to glacier survival. In areas such as Siberia and parts of Antarctica, the lack of adequate precipitation prevents glacier development. Dokriyani: This glacier is believed to be as old as the Himalayan Mountains. Dokriani 'Bamak' is a well-developed medium sized glacier of the Bhagirathi basin.
The glacier is 5 km long and flows in a northwest direction terminating at an elevation of 3,800 m. It originates at an altitude of 13 000 feet in Uttaranchal's Garhwal district. It is one of the most studied glaciers in the world. A recent study says that it has been shrinking by a few metres every year. Gangotri: This is located in Uttaranchal's Tehri Garhwal. One of the oldest glaciers in the Chaukhamba range, it is where the river Ganga originates. The Gangotri is not a single valley glacier, but a combination of several other glaciers that are fed to it and form a huge mass of ice. The glacier covers 28km and terminates at Gaumukh (4,000m).
Other Rivers
Brahmaputra: This mighty river rises in western Tibet in the Manasarovar region. It flows eastwards through the Himalayas, curves back across Arunachal Pradesh and Assam, then turns south to join the Padma and Ganga in Bangladesh and finally enters the Bay of Bengal. It is known by different names in different regions: as it flows through Tibet it is known as the Tsangpo., In the north-eastern states of Arunachal Pradesh and Assam, it is known as the Siang or Dihang.
It is longer and more voluminous than the Ganga, and gushes down with enormous force for most of its course through the mountain regions and the forests of north-east India. A unique feature of this river is that it is navigable even at a height of 10 000 feet. Indus: Known as the Sindhu in ancient times, the Indus was the cradle of India's great Indus Valley civilization. It has its source near Manasarovar close to southwestern Tibet, at an altitude of 16,000 feet and flows westward, through the Himalayas into Ladakh, and then through Sind and Punjab in Pakistan into the Arabian Sea.
After flowing eleven miles beyond Leh, the Indus is joined by its first tributary, the Zanskar. When it enters the plains, its famous five tributaries - the Jhelum, Chenab, Ravi, Beas, and Sutlej - that give Punjab its name (land of the five rivers) join it. The name India is said to have its roots in Sindhu (Indus), the great river that constitutes the most imposing feature of that part of the subcontinent, home to some of the earliest civilizations.The river Sindhu has been invoked numerous times in the Vedic literature together with those of other gods and goddesses.
Mahanadi: This river is considered the lifeline of Orissa, through which it flows. It originates in south-eastern Madhya Pradesh near Raipur. In the upper drainage basin of the Mahanadi, which is centred on the Chhattisgarh Plain, periodic droughts contrast with the situation in the delta region where floods may damage the crops in what is known as the rice bowl of Orissa. The Hirakud Dam, constructed in the middle reaches of the Mahanadi, has helped in alleviating these adverse effects by creating a reservoir.
It is longer and more voluminous than the Ganga, and gushes down with enormous force for most of its course through the mountain regions and the forests of north-east India. A unique feature of this river is that it is navigable even at a height of 10 000 feet. Indus: Known as the Sindhu in ancient times, the Indus was the cradle of India's great Indus Valley civilization. It has its source near Manasarovar close to southwestern Tibet, at an altitude of 16,000 feet and flows westward, through the Himalayas into Ladakh, and then through Sind and Punjab in Pakistan into the Arabian Sea.
After flowing eleven miles beyond Leh, the Indus is joined by its first tributary, the Zanskar. When it enters the plains, its famous five tributaries - the Jhelum, Chenab, Ravi, Beas, and Sutlej - that give Punjab its name (land of the five rivers) join it. The name India is said to have its roots in Sindhu (Indus), the great river that constitutes the most imposing feature of that part of the subcontinent, home to some of the earliest civilizations.The river Sindhu has been invoked numerous times in the Vedic literature together with those of other gods and goddesses.
Mahanadi: This river is considered the lifeline of Orissa, through which it flows. It originates in south-eastern Madhya Pradesh near Raipur. In the upper drainage basin of the Mahanadi, which is centred on the Chhattisgarh Plain, periodic droughts contrast with the situation in the delta region where floods may damage the crops in what is known as the rice bowl of Orissa. The Hirakud Dam, constructed in the middle reaches of the Mahanadi, has helped in alleviating these adverse effects by creating a reservoir.
Major Rivers of India
Ganga This is considered the holiest of all the great rivers of India. It has its source at the Gangotri glacier, where it flows from the cave Goumukh, as the Bhagirathi, which then joins the River Alaknanda as it flows towards Devaprayag. The largest tributary of the river is the Ghaghara, which flows from the northern Nepal region and joins it before Patna in Bihar. Another major tributary is the Yamuna originating in the Yamunotri glacier, and flows through Delhi and Agra. Others are the Gomti, Gandak, Son, Kosi, Chambal, Sarda, etc.
The Ganga is the lifeline for more than 500 million people living along its banks. The water of the river Ganges is considered so sacred that people keep it in their homes for use in prayers on important occasions such as at the time of death. Most cities along the river do not have sewage treatment plants and those that do have them can handle only part of the waste water. Millions of tonnes of untreated sewage are dumped daily into the river from the cities that lie along its banks. Bathing and washing also contribute to the pollution as most of the soap that is used is made from chemical substances.
The river is also polluted by human and animal faeces. Industrial units that lie along the banks of the river discharge all the waste into the river and only a few of them have proper treatment facilities. Yamuna : Rising from the Yamunotri glacier in the Tehri Garhwal District in the Himalayas, the Yamuna flows for about 1380 km almost parallel to the Ganga till they meet at Allahabad. It flows through a number of important towns, Delhi, Mathura, Brindaban, and Agra to name some. Since ancient times, the Doab region, where the Ganga and the Yamuna flow, has been considered one of the most fertile areas in the subcontinent.
Today however, this majestic river is polluted with domestic waste, silt, and industrial waste. The 22-km stretch between Wazirabad and the Okhla barrage in Delhi is only 2% of the catchment area, but it contributes about 80% of the river's total pollution load. The Hindon Canal also discharges waste from Uttar Pradesh in this stretch. Among the many casualties are birds and fish. There was a time when bird watchers had identified as many as 30 species of birds near the Yamuna, many of them exotic, such as the red-crested pochard and the godwit.
The Ganga is the lifeline for more than 500 million people living along its banks. The water of the river Ganges is considered so sacred that people keep it in their homes for use in prayers on important occasions such as at the time of death. Most cities along the river do not have sewage treatment plants and those that do have them can handle only part of the waste water. Millions of tonnes of untreated sewage are dumped daily into the river from the cities that lie along its banks. Bathing and washing also contribute to the pollution as most of the soap that is used is made from chemical substances.
The river is also polluted by human and animal faeces. Industrial units that lie along the banks of the river discharge all the waste into the river and only a few of them have proper treatment facilities. Yamuna : Rising from the Yamunotri glacier in the Tehri Garhwal District in the Himalayas, the Yamuna flows for about 1380 km almost parallel to the Ganga till they meet at Allahabad. It flows through a number of important towns, Delhi, Mathura, Brindaban, and Agra to name some. Since ancient times, the Doab region, where the Ganga and the Yamuna flow, has been considered one of the most fertile areas in the subcontinent.
Today however, this majestic river is polluted with domestic waste, silt, and industrial waste. The 22-km stretch between Wazirabad and the Okhla barrage in Delhi is only 2% of the catchment area, but it contributes about 80% of the river's total pollution load. The Hindon Canal also discharges waste from Uttar Pradesh in this stretch. Among the many casualties are birds and fish. There was a time when bird watchers had identified as many as 30 species of birds near the Yamuna, many of them exotic, such as the red-crested pochard and the godwit.
Rivers
Most ancient civilizations grew along the banks of rivers. Even today, millions of people all over the world live on the banks of rivers and depend on them for their survival. All of us have seen a river - large or small, either flowing through our town, or somewhere else. Rivers are nothing more than surface water flowing down from a higher altitude to a lower altitude due to the pull of gravity. One river might have its source in a glacier, another in a spring or a lake. Rivers carry dissolved minerals, organic compounds, small grains of sand, gravel, and other material as they flow downstream.
Rivers begin as small streams, which grow wider as smaller streams and rivers join them along their course across theland. Eventually they flow into seas or oceans. Most rivers With the exception of the Nile, flow towards the Equator. The flow in most rivers is not uniform, which means that sometimes there are floods and sometimes no water flows in them. Flood control projects attempt to reduce the variation in flow. Unfortunately most of the world's major rivers are heavily polluted, but two of the world's largest river systems-the Amazon, that drains a vast area of South America and the Congo in sub-Saharan Africa- remain relatively healthy.
This is because both have few industries and a small human population in their watersheds. The Nile, 6695 km long, and the Amazon 6437 km long, are the world's two longest rivers. Sometimes, measurements of their lengths can vary according to the criteria used for measurement. An Arab philosopher and physician Avicenna suggested, nearly 1000 years ago, that landscapes changed largely as a result of the action of running water. His views were largely ignored until the 16th century.
The longest river in Asia is the Yangtze, which is 5472 km long. The world's highest waterfall are the Angel Falls in Venezuela, 979 m high, over 780 m of which is an uninterrupted drop. India has a large number of rivers that are lifelines for the millions living along their banks. These rivers can be categorized into four groups: Rivers that flow down from the Himalayas and are supplied by melting snow and glaciers. This is why these are perennial, that is, they never dry up during the year The Deccan Plateau rivers, which depend on rainfall for their water, The coastal rivers, especially those on the west coast, which are short and do not retain water throughout the year, The rivers in the inland drainage basin of west Rajasthan, which depend on the rains. These rivers normally drain towards silt lakes or flow into the sand.
Rivers begin as small streams, which grow wider as smaller streams and rivers join them along their course across theland. Eventually they flow into seas or oceans. Most rivers With the exception of the Nile, flow towards the Equator. The flow in most rivers is not uniform, which means that sometimes there are floods and sometimes no water flows in them. Flood control projects attempt to reduce the variation in flow. Unfortunately most of the world's major rivers are heavily polluted, but two of the world's largest river systems-the Amazon, that drains a vast area of South America and the Congo in sub-Saharan Africa- remain relatively healthy.
This is because both have few industries and a small human population in their watersheds. The Nile, 6695 km long, and the Amazon 6437 km long, are the world's two longest rivers. Sometimes, measurements of their lengths can vary according to the criteria used for measurement. An Arab philosopher and physician Avicenna suggested, nearly 1000 years ago, that landscapes changed largely as a result of the action of running water. His views were largely ignored until the 16th century.
The longest river in Asia is the Yangtze, which is 5472 km long. The world's highest waterfall are the Angel Falls in Venezuela, 979 m high, over 780 m of which is an uninterrupted drop. India has a large number of rivers that are lifelines for the millions living along their banks. These rivers can be categorized into four groups: Rivers that flow down from the Himalayas and are supplied by melting snow and glaciers. This is why these are perennial, that is, they never dry up during the year The Deccan Plateau rivers, which depend on rainfall for their water, The coastal rivers, especially those on the west coast, which are short and do not retain water throughout the year, The rivers in the inland drainage basin of west Rajasthan, which depend on the rains. These rivers normally drain towards silt lakes or flow into the sand.
Threat of Coral reefs to Ecosystem
While coral reefs are sensitive to environmental changes, they appear to be able to recover effectively from physical disturbance or temporary pollution events provided the water quality is generally high. For example, the corals in Kaneohe Bay, Hawaii, for the most part recovered from severe overgrowth of algae after sewage inputs were diverted away from the Bay. The world has woken up to the magnitude of the problem and has taken steps to halt this degradation of one of the richest eco systems.
The Convention on International Trade in Endangered Species of Wild Fauna and Flora, or CITES, has classified many corals as threatened species. The establishment of marine sanctuaries or preserves may help ensure the availability of this ecosystem in the years to come. The Great Barrier Reef Marine Park was established in 1975 and is the largest project undertaken to preserve the coral reef in the world. Initiatives for the preservation of coral reefs in India have been undertaken on a large scale in the Wandur Marine National Park in the Andaman Nicobar islands.
People on their part can play a role in preventing this depletion. Corals should not be collected, either alive or dead. All waste should be treated before it is released into the sea and no waste is to be dumped directly into the water. Once this awareness is built in the people the well being of these reefs can be ensured. The coral reef ecosystem is a diverse collection of species that interact with each other and the physical environment. The numerous species residing and depending on coral reefs represent a bank containing the genetic diversity necessary for adaptation to changes in the environment.
Sponges have been an important part of the coral reef ecosystem. Sea anemones provide shelter to the fish and other creatures in the reefs. Fishes play a vital role in the reef's food web, acting as both predators and prey. Bryozoans are microscopic invertebrates that form branching colonies over coral skeletons and reef debris, cementing the reef structure. The reef is also home to a variety of worms, shrimps, crabs, lobsters, starfish, sea cucumbers, and sea urchins. Octopuses, squids, clams, scallops, marine snails, and also some species of sharks, skates, and rays live on or near the reef.
The Convention on International Trade in Endangered Species of Wild Fauna and Flora, or CITES, has classified many corals as threatened species. The establishment of marine sanctuaries or preserves may help ensure the availability of this ecosystem in the years to come. The Great Barrier Reef Marine Park was established in 1975 and is the largest project undertaken to preserve the coral reef in the world. Initiatives for the preservation of coral reefs in India have been undertaken on a large scale in the Wandur Marine National Park in the Andaman Nicobar islands.
People on their part can play a role in preventing this depletion. Corals should not be collected, either alive or dead. All waste should be treated before it is released into the sea and no waste is to be dumped directly into the water. Once this awareness is built in the people the well being of these reefs can be ensured. The coral reef ecosystem is a diverse collection of species that interact with each other and the physical environment. The numerous species residing and depending on coral reefs represent a bank containing the genetic diversity necessary for adaptation to changes in the environment.
Sponges have been an important part of the coral reef ecosystem. Sea anemones provide shelter to the fish and other creatures in the reefs. Fishes play a vital role in the reef's food web, acting as both predators and prey. Bryozoans are microscopic invertebrates that form branching colonies over coral skeletons and reef debris, cementing the reef structure. The reef is also home to a variety of worms, shrimps, crabs, lobsters, starfish, sea cucumbers, and sea urchins. Octopuses, squids, clams, scallops, marine snails, and also some species of sharks, skates, and rays live on or near the reef.
Ecosystem
Corals are small, sedentary marine animals that occur in dense colonies in warm shallow waters of oceans. Reef-building corals are scattered throughout the tropical and subtropical western Atlantic and Indo-Pacific oceans, generally between 30 degrees North and 30 degrees South latitudes. Coral reefs are formed by the skeleton remains of many generations of stony corals. Massive reef structures are built over thousands of years by tiny coral polyps aided by minute algae (zooxanthellae) that live in their tissues, calcifying algae, and other organisms that secrete calcium carbonate and adhesives.
Reef- building corals are generally found at depths of less than 46 m, where there is sunlight and clear water through which the sunlight penetrates better. Reef-building corals, along with the algae, require warm ocean temperatures (20–28° C) and are therefore found along the eastern shores of major land masses where the water is warmer. These reefs are amongst the earth’s oldest living communities of plants and animals. They vary in shape, size and colour. Coral reefs are sometimes referred to as ‘tropical rainforests of the deep’ since they are one of the most diverse, productive, and beautiful marine ecosystems in the world.
The extraordinary diversity of reefs makes them biologically important and, like rainforests, they have provided valuable scientific insights into the nature of underwater ecology. It is a diverse collection of species that interact with each other and the physical environment. The sun is the initial source of energy for this ecosystem. They are considered to be one of the most sensitive to any change. When they are environmentally stressed they lose much of the algae that gives them the colour along with other pigments.
When this happens the corals appear white in colour and are referred to as bleached. Excessive growth and accumulation of phytoplankton and seaweed would be detrimental to coral vitality and diversity, and low nutrient conditions are needed to prevent this. Diverse and abundant populations of grazing fish and invertebrates also keep the growth down. The crown of thorns, a starfish, is a well- known predator of coral. Large numbers of these starfish can devastate reefs, leaving behind only the calcium carbonate skeletons. Parrotfish use chisel-like teeth to nibble on hard corals and eat the algae within the coral. Eels are one of the reef's largest predators and feed on the small fishes, octopuses, shrimps, and crabs.
Reef- building corals are generally found at depths of less than 46 m, where there is sunlight and clear water through which the sunlight penetrates better. Reef-building corals, along with the algae, require warm ocean temperatures (20–28° C) and are therefore found along the eastern shores of major land masses where the water is warmer. These reefs are amongst the earth’s oldest living communities of plants and animals. They vary in shape, size and colour. Coral reefs are sometimes referred to as ‘tropical rainforests of the deep’ since they are one of the most diverse, productive, and beautiful marine ecosystems in the world.
The extraordinary diversity of reefs makes them biologically important and, like rainforests, they have provided valuable scientific insights into the nature of underwater ecology. It is a diverse collection of species that interact with each other and the physical environment. The sun is the initial source of energy for this ecosystem. They are considered to be one of the most sensitive to any change. When they are environmentally stressed they lose much of the algae that gives them the colour along with other pigments.
When this happens the corals appear white in colour and are referred to as bleached. Excessive growth and accumulation of phytoplankton and seaweed would be detrimental to coral vitality and diversity, and low nutrient conditions are needed to prevent this. Diverse and abundant populations of grazing fish and invertebrates also keep the growth down. The crown of thorns, a starfish, is a well- known predator of coral. Large numbers of these starfish can devastate reefs, leaving behind only the calcium carbonate skeletons. Parrotfish use chisel-like teeth to nibble on hard corals and eat the algae within the coral. Eels are one of the reef's largest predators and feed on the small fishes, octopuses, shrimps, and crabs.
Oil Spills in Water
Among the most dangerous of all water pollutants is fuel oil. Oil spills from tankers at sea or leaks from underground storage tanks on land are very difficult to control as oil tends to spread very fast, affecting a large area in a very short time. They are a major menace to the environment as they cause severe damage to surrounding ecosystems. Oil spills at sea decrease the oxygen level in the water and cause grave harm to the creatures living in the sea. Since crude oil is lighter than water, it floats on the surface and poses the threat of swift-spreading fire.
Oil spills are rather common as oil tankers can meet with accidents either in deep sea or offshore, while waiting to be loaded or unloaded. During the Gulf War, several oil reservoirs were destroyed at sea and the effect on marine life was devastating. Seabirds and fish were washed ashore, their bodies covered with oil. On land crude is transported through pipelines or tankers which can get damaged and spew out crude oil over the land, thereby contaminating it. Enormous quantities of organic and inorganic compounds are released into the environment each year as a result of human activities.
In some cases these releases are deliberate and well regulated (e.g. industrial emissions) while in other cases they are accidental (e.g. chemical or oil spills). Petroleum and its products are one of the most common environmental pollutants. They are a fire hazard, threat to marine life, and a source of air and groundwater pollution. They contaminate land and water bodies by accidental spills like the Alaska Oil spill in 1989 and oil spills during the Gulf War, leakage from pipelines, and other human activities. Detoxification of the contaminated sites is expensive and time consuming by conventional chemical or physical methods.
Bioremediation consists of using naturally occurring or laboratory cultivated micro-organisms to reduce or eliminate toxic pollutants. Petroleum products are a rich source of energy and some organisms are able to take advantage of this and use hydrocarbons as a source of food and energy. This results in the breakdown of these complex compounds into simpler forms such as carbon dioxide and water. Bioremediation thus involves detoxifying hazardous substances instead of merely transferring them from one medium to another. This process is less disruptive and can be carried out at the site which reduces the need of transporting these toxic materials to separate treatment sites.
Oil spills are rather common as oil tankers can meet with accidents either in deep sea or offshore, while waiting to be loaded or unloaded. During the Gulf War, several oil reservoirs were destroyed at sea and the effect on marine life was devastating. Seabirds and fish were washed ashore, their bodies covered with oil. On land crude is transported through pipelines or tankers which can get damaged and spew out crude oil over the land, thereby contaminating it. Enormous quantities of organic and inorganic compounds are released into the environment each year as a result of human activities.
In some cases these releases are deliberate and well regulated (e.g. industrial emissions) while in other cases they are accidental (e.g. chemical or oil spills). Petroleum and its products are one of the most common environmental pollutants. They are a fire hazard, threat to marine life, and a source of air and groundwater pollution. They contaminate land and water bodies by accidental spills like the Alaska Oil spill in 1989 and oil spills during the Gulf War, leakage from pipelines, and other human activities. Detoxification of the contaminated sites is expensive and time consuming by conventional chemical or physical methods.
Bioremediation consists of using naturally occurring or laboratory cultivated micro-organisms to reduce or eliminate toxic pollutants. Petroleum products are a rich source of energy and some organisms are able to take advantage of this and use hydrocarbons as a source of food and energy. This results in the breakdown of these complex compounds into simpler forms such as carbon dioxide and water. Bioremediation thus involves detoxifying hazardous substances instead of merely transferring them from one medium to another. This process is less disruptive and can be carried out at the site which reduces the need of transporting these toxic materials to separate treatment sites.
Preventions of Water Pollution
Water-borne epidemics and health hazards in the aquatic environment are mainly due to improper management of water resources. Proper management of water resources has become the need of the hour as this would ultimately lead to a cleaner and healthier environment. In order to prevent the spread of water-borne infectious diseases, people should take adequate precautions. The city water supply should be properly checked and necessary steps taken to disinfect it. Water pipes should be regularly checked for leaks and cracks.
At home, the water should be boiled, filtered, or other methods and necessary steps taken to ensure that it is free from infection. In Minamata, Japan, inorganic mercury was used in the industrial production of acetaldehyde. It was discharged into the nearby bay as waste water and was ingested by organisms in the bottom sediments. Fish and other creatures in the sea were soon contaminated and eventually residents of this area who consumed the fish suffered from MeHg (methyl mercury) intoxication, later known as the Minamata disease.
The disease was first detected in 1956 but the mercury emissions continued until 1968. But even after the emission of mercury stopped, the bottom sediment of the polluted water contained high levels of this mercury. Various measures were taken to deal with this disease. Environmental pollution control, which included cessation of the mercury process; industrial effluent control, environmental restoration of the bay; and restrictions on the intake of fish from the bay. This apart research and investigative activities were promoted assiduously, and compensation and help was offered by the Japanese.
Government to all those affected by the disease. The Minamata disease proved a turning point, towards progress in environment protection measures. This experience clearly showed that health and environment considerations must be integrated into the process of economic and industrial development from an early stage. The city water supply should be properly checked and necessary steps taken to disinfect it. Water pipes should be regularly checked for leaks and cracks. At home, the water should be boiled, filtered, or other methods and necessary steps taken to ensure that it is free from infection.
Diseases of water Pollution
Water-borne diseases are infectious diseases spread primarily through contaminated water. Though these diseases are spread either directly or through flies or filth, water is the chief medium for spread of these diseases and hence they are termed as water-borne diseases. Most intestinal (enteric) diseases are infectious and are transmitted through faecal waste. Pathogens – which include virus, bacteria, protozoa, and parasitic worms – are disease-producing agents found in the faeces of infected persons.
These diseases are more prevalent in areas with poor sanitary conditions. These pathogens travel through water sources and interfuses directly through persons handling food and water. Since these diseases are highly infectious, extreme care and hygiene should be maintained by people looking after an infected patient. Hepatitis, cholera, dysentery, and typhoid are the more common water-borne diseases that affect large populations in the tropical regions. A large number of chemicals that either exist naturally in the land or are added due to human activity dissolve in the water, thereby contaminating it and leading to various diseases.
Pesticides. The organophosphates and the carbonates present in pesticides affect and damage the nervous system and can cause cancer. Some of the pesticides contain carcinogens that exceed recommended levels. They contain chlorides that cause reproductive and endocrinal damage. Lead. Lead is hazardous to health as it accumulates in the body and affects the central nervous system. Children and pregnant women are most at risk. Fluoride. Excess fluorides can cause yellowing of the teeth and damage to the spinal cord and other crippling diseases.
Nitrates. Drinking water that gets contaminated with nitrates can prove fatal especially to infants that drink formula milk as it restricts the amount of oxygen that reaches the brain causing the ‘blue baby’ syndrome. It is also linked to digestive tract cancers. It causes algae to bloom resulting in eutrophication in surface water. Petrochemicals. Benzene and other petrochemicals can cause cancer even at low exposure levels. Chlorinated solvents. These are linked to reproduction disorders and to some cancers. Arsenic. Arsenic poisoning through water can cause liver and nervous system damage, vascular diseases and also skin cancer. Other heavy metals. –Heavy metals cause damage to the nervous system and the kidney, and other metabolic disruptions.
These diseases are more prevalent in areas with poor sanitary conditions. These pathogens travel through water sources and interfuses directly through persons handling food and water. Since these diseases are highly infectious, extreme care and hygiene should be maintained by people looking after an infected patient. Hepatitis, cholera, dysentery, and typhoid are the more common water-borne diseases that affect large populations in the tropical regions. A large number of chemicals that either exist naturally in the land or are added due to human activity dissolve in the water, thereby contaminating it and leading to various diseases.
Pesticides. The organophosphates and the carbonates present in pesticides affect and damage the nervous system and can cause cancer. Some of the pesticides contain carcinogens that exceed recommended levels. They contain chlorides that cause reproductive and endocrinal damage. Lead. Lead is hazardous to health as it accumulates in the body and affects the central nervous system. Children and pregnant women are most at risk. Fluoride. Excess fluorides can cause yellowing of the teeth and damage to the spinal cord and other crippling diseases.
Nitrates. Drinking water that gets contaminated with nitrates can prove fatal especially to infants that drink formula milk as it restricts the amount of oxygen that reaches the brain causing the ‘blue baby’ syndrome. It is also linked to digestive tract cancers. It causes algae to bloom resulting in eutrophication in surface water. Petrochemicals. Benzene and other petrochemicals can cause cancer even at low exposure levels. Chlorinated solvents. These are linked to reproduction disorders and to some cancers. Arsenic. Arsenic poisoning through water can cause liver and nervous system damage, vascular diseases and also skin cancer. Other heavy metals. –Heavy metals cause damage to the nervous system and the kidney, and other metabolic disruptions.
Contaminants of Water
Ground water can be contaminated through various sources and some of these are mentioned below. Pesticides. Run-off from farms, backyards, and golf courses contain pesticides such as DDT that in turn contaminate the water. Leechate from landfill sites is another major contaminating source. Its effects on the ecosystems and health are endocrine and reproductive damage in wildlife. Groundwater is susceptible to contamination, as pesticides are mobile in the soil. It is a matter of concern as these chemicals are persistent in the soil and water.
Sewage. Untreated or inadequately treated municipal sewage is a major source of groundwater and surface water pollution in the developing countries. The organic material that is discharged with municipal waste into the watercourses uses substantial oxygen for biological degradation thereby upsetting the ecological balance of rivers and lakes. Sewage also carries microbial pathogens that are the cause of the spread of disease. Nutrients. Domestic waste water, agricultural run-off, and industrial effluents contain phosphorus and nitrogen, fertilizer run-off, manure from livestock operations, which increase the level of nutrients in water bodies and can cause eutrophication in the lakes and rivers and continue on to the coastal areas.
The nitrates come mainly from the fertilizer that is added to the fields. Excessive use of fertilizers cause nitrate contamination of groundwater, with the result that nitrate levels in drinking water is far above the safety levels recommended. Good agricultural practices can help in reducing the amount of nitrates in the soil and thereby lower its content in the water. Synthetic organics. Many of the 100 000 synthetic compounds in use today are found in the aquatic environment and accumulate in the food chain. POPs or Persistent organic pollutants, represent the most harmful element for the ecosystem and for human health, for example, industrial chemicals and agricultural pesticides.
These chemicals can accumulate in fish and cause serious damage to human health. Where pesticides are used on a large-scale, groundwater gets contaminated and this leads to the chemical contamination of drinking water. Acidification. Acidification of surface water, mainly lakes and reservoirs, is one of the major environmental impacts of transport over long distance of air pollutants such as sulphur dioxide from power plants, other heavy industry such as steel plants, and motor vehicles. This problem is more severe in the US and in parts of Europe.
Sewage. Untreated or inadequately treated municipal sewage is a major source of groundwater and surface water pollution in the developing countries. The organic material that is discharged with municipal waste into the watercourses uses substantial oxygen for biological degradation thereby upsetting the ecological balance of rivers and lakes. Sewage also carries microbial pathogens that are the cause of the spread of disease. Nutrients. Domestic waste water, agricultural run-off, and industrial effluents contain phosphorus and nitrogen, fertilizer run-off, manure from livestock operations, which increase the level of nutrients in water bodies and can cause eutrophication in the lakes and rivers and continue on to the coastal areas.
The nitrates come mainly from the fertilizer that is added to the fields. Excessive use of fertilizers cause nitrate contamination of groundwater, with the result that nitrate levels in drinking water is far above the safety levels recommended. Good agricultural practices can help in reducing the amount of nitrates in the soil and thereby lower its content in the water. Synthetic organics. Many of the 100 000 synthetic compounds in use today are found in the aquatic environment and accumulate in the food chain. POPs or Persistent organic pollutants, represent the most harmful element for the ecosystem and for human health, for example, industrial chemicals and agricultural pesticides.
These chemicals can accumulate in fish and cause serious damage to human health. Where pesticides are used on a large-scale, groundwater gets contaminated and this leads to the chemical contamination of drinking water. Acidification. Acidification of surface water, mainly lakes and reservoirs, is one of the major environmental impacts of transport over long distance of air pollutants such as sulphur dioxide from power plants, other heavy industry such as steel plants, and motor vehicles. This problem is more severe in the US and in parts of Europe.
Health Impacts of water Pollution
It is a well-known fact that clean water is absolutely essential for healthy living. Adequate supply of fresh and clean drinking water is a basic need for all human beings on the earth, yet it has been observed that millions of people worldwide are deprived of this. Freshwater resources all over the world are threatened not only by over exploitation and poor management but also by ecological degradation. The main source of freshwater pollution can be attributed to discharge of untreated waste, dumping of industrial effluent, and run-off from agricultural fields.
Industrial growth, urbanization and the increasing use of synthetic organic substances have serious and adverse impacts on freshwater bodies. It is a generally accepted fact that the developed countries suffer from problems of chemical discharge into the water sources mainly groundwater, while developing countries face problems of agricultural run-off in water sources. Polluted water like chemicals in drinking water causes problem to health and leads to water-borne diseases which can be prevented by taking measures can be taken even at the household level.
Many areas of groundwater and surface water are now contaminated with heavy metals, POPs (persistent organic pollutants), and nutrients that have an adverse affect on health. Water-borne diseases and water-caused health problems are mostly due to inadequate and incompetent management of water resources. Safe water for all can only be assured when access, sustainability, and equity can be guaranteed. Access can be defined as the number of people who are guaranteed safe drinking water and sufficient quantities of it.
There has to be an effort to sustain it, and there has to be a fair and equal distribution of water to all segments of the society. Urban areas generally have a higher coverage of safe water than the rural areas. Even within an area there is variation: areas that can pay for the services have access to safe water whereas areas that cannot pay for the services have to make do with water from hand pumps and other sources. In the urban areas water gets contaminated in many different ways, some of the most common reasons being leaky water pipe joints in areas where the water pipe and sewage line pass close together. Sometimes the water gets polluted at source due to various reasons and mainly due to inflow of sewage into the source.
Industrial growth, urbanization and the increasing use of synthetic organic substances have serious and adverse impacts on freshwater bodies. It is a generally accepted fact that the developed countries suffer from problems of chemical discharge into the water sources mainly groundwater, while developing countries face problems of agricultural run-off in water sources. Polluted water like chemicals in drinking water causes problem to health and leads to water-borne diseases which can be prevented by taking measures can be taken even at the household level.
Many areas of groundwater and surface water are now contaminated with heavy metals, POPs (persistent organic pollutants), and nutrients that have an adverse affect on health. Water-borne diseases and water-caused health problems are mostly due to inadequate and incompetent management of water resources. Safe water for all can only be assured when access, sustainability, and equity can be guaranteed. Access can be defined as the number of people who are guaranteed safe drinking water and sufficient quantities of it.
There has to be an effort to sustain it, and there has to be a fair and equal distribution of water to all segments of the society. Urban areas generally have a higher coverage of safe water than the rural areas. Even within an area there is variation: areas that can pay for the services have access to safe water whereas areas that cannot pay for the services have to make do with water from hand pumps and other sources. In the urban areas water gets contaminated in many different ways, some of the most common reasons being leaky water pipe joints in areas where the water pipe and sewage line pass close together. Sometimes the water gets polluted at source due to various reasons and mainly due to inflow of sewage into the source.
Agriculture and Water
Shelter belts of trees and bushes along the edge of agricultural fields slow down the wind speed and reduce evaporation and erosion. Planting of trees, grass, and bushes breaks the force of rain and helps rainwater penetrate the soil. Fog and dew contain substantial amounts of water that can be used directly by adapted plant species. Artificial surfaces such as netting-surfaced traps or polyethylene sheets can be exposed to fog and dew. The resulting water can be used for crops. Contour farming is adopted in hilly areas and in lowland areas for paddy fields.
Farmers recognize the efficiency of contour-based systems for conserving soil and water. Salt-resistant varieties of crops have also been developed recently. Because these grow in saline areas, overall agricultural productivity is increased without making additional demands on freshwater sources. Thus, this is a good water conservation strategy. Transfer of water from surplus areas to deficit areas by inter-linking water systems through canals, etc. Desalination technologies such as distillation, electro-dialysis and reverse osmosis are available. Use of efficient watering systems such as drip irrigation and sprinklers will reduce the water consumption by plants.
The most important step in the direction of finding solutions to issues of water and environmental conservation is to change people's attitudes and habits¾this includes each one of us. Conserve water because it is the right thing to do. We can follow some of the simple things that have been listed below and contribute to water conservation. Try to do one thing each day that will result in saving water. Don't worry if the savings are minimal¾every drop counts! You can make a difference. Remember to use only the amount you actually need. Form a group of water-conscious people and encourage your friends and neighbours to be part of this group.
Promote water conservation in community newsletters and on bulletin boards. Encourage your friends, neighbours and co-workers to also contribute. Encourage your family to keep looking for new ways to conserve water in and around your home. Make sure that your home is leak-free. Many homes have leaking pipes that go unnoticed. Do not leave the tap running while you are brushing your teeth or soaping your face. See that there are no leaks in the toilet tank. You can check this by adding colour to the tank. If there is a leak, colour will appear in the toilet bowl within 30 minutes. (Flush as soon as the test is done, since food colouring may stain the tank.) Avoid flushing the toilet unnecessarily. Put a brick or any other device that occupies space to cut down on the amount of water needed for each flush. When washing the car, use water from a bucket and not a hosepipe.
Farmers recognize the efficiency of contour-based systems for conserving soil and water. Salt-resistant varieties of crops have also been developed recently. Because these grow in saline areas, overall agricultural productivity is increased without making additional demands on freshwater sources. Thus, this is a good water conservation strategy. Transfer of water from surplus areas to deficit areas by inter-linking water systems through canals, etc. Desalination technologies such as distillation, electro-dialysis and reverse osmosis are available. Use of efficient watering systems such as drip irrigation and sprinklers will reduce the water consumption by plants.
The most important step in the direction of finding solutions to issues of water and environmental conservation is to change people's attitudes and habits¾this includes each one of us. Conserve water because it is the right thing to do. We can follow some of the simple things that have been listed below and contribute to water conservation. Try to do one thing each day that will result in saving water. Don't worry if the savings are minimal¾every drop counts! You can make a difference. Remember to use only the amount you actually need. Form a group of water-conscious people and encourage your friends and neighbours to be part of this group.
Promote water conservation in community newsletters and on bulletin boards. Encourage your friends, neighbours and co-workers to also contribute. Encourage your family to keep looking for new ways to conserve water in and around your home. Make sure that your home is leak-free. Many homes have leaking pipes that go unnoticed. Do not leave the tap running while you are brushing your teeth or soaping your face. See that there are no leaks in the toilet tank. You can check this by adding colour to the tank. If there is a leak, colour will appear in the toilet bowl within 30 minutes. (Flush as soon as the test is done, since food colouring may stain the tank.) Avoid flushing the toilet unnecessarily. Put a brick or any other device that occupies space to cut down on the amount of water needed for each flush. When washing the car, use water from a bucket and not a hosepipe.
Agriculture
Conservation of water in the agricultural sector is essential since water is necessary for the growth of plants and crops. A depleting water table and a rise in salinity due to overuse of chemical fertilizers and pesticides has made matters serious. Various methods of water harvesting and recharging have been and are being applied all over the world to tackle the problem. In areas where rainfall is low and water is scarce, the local people have used simple techniques that are suited to their region and reduce the demand for water.
In India's arid and semi-arid areas, the 'tank' system is traditionally the backbone of agricultural production. Tanks are constructed either by bunding or by excavating the ground and collecting rainwater.Rajasthan, located in the Great Indian Desert, receives hardly any rainfall, but people have adapted to the harsh conditions by collecting whatever rain falls. Large bunds to create reservoirs known as khadin, dams called johads, tanks, and other methods were applied to check water flow and accumulate run-off. At the end of the monsoon season, water from these structures was used to cultivate crops.
Similar systems were developed in other parts of the country. These are known by various local names ¾ jal talais in Uttar Pradesh, the haveli system in Madhya Pradesh, ahar in Bihar, and so on. Simple techniques can be used to reduce the demand for water. The underlying principle is that only part of the rainfall or irrigation water is taken up by plants, the rest percolates into the deep groundwater, or is lost by evaporation from the surface. Therefore, by improving the efficiency of water use, and by reducing its loss due to evaporation, we can reduce water demand.
There are numerous methods to reduce such losses and to improve soil moisture. Some of them are listed below. Mulching, i.e., the application of organic or inorganic material such as plant debris, compost, etc., slows down the surface run-off, improves the soil moisture, reduces evaporation losses and improves soil fertility. Soil covered by crops, slows down run-off and minimizes evaporation losses. Hence, fields should not be left bare for long periods of time. Ploughing helps to move the soil around. As a consequence it retains more water thereby reducing evaporation.
In India's arid and semi-arid areas, the 'tank' system is traditionally the backbone of agricultural production. Tanks are constructed either by bunding or by excavating the ground and collecting rainwater.Rajasthan, located in the Great Indian Desert, receives hardly any rainfall, but people have adapted to the harsh conditions by collecting whatever rain falls. Large bunds to create reservoirs known as khadin, dams called johads, tanks, and other methods were applied to check water flow and accumulate run-off. At the end of the monsoon season, water from these structures was used to cultivate crops.
Similar systems were developed in other parts of the country. These are known by various local names ¾ jal talais in Uttar Pradesh, the haveli system in Madhya Pradesh, ahar in Bihar, and so on. Simple techniques can be used to reduce the demand for water. The underlying principle is that only part of the rainfall or irrigation water is taken up by plants, the rest percolates into the deep groundwater, or is lost by evaporation from the surface. Therefore, by improving the efficiency of water use, and by reducing its loss due to evaporation, we can reduce water demand.
There are numerous methods to reduce such losses and to improve soil moisture. Some of them are listed below. Mulching, i.e., the application of organic or inorganic material such as plant debris, compost, etc., slows down the surface run-off, improves the soil moisture, reduces evaporation losses and improves soil fertility. Soil covered by crops, slows down run-off and minimizes evaporation losses. Hence, fields should not be left bare for long periods of time. Ploughing helps to move the soil around. As a consequence it retains more water thereby reducing evaporation.
Rain water Harvesting
In urban areas, the construction of houses, footpaths and roads has left little exposed earth for water to soak in. In parts of the rural areas of India, floodwater quickly flows to the rivers, which then dry up soon after the rains stop. If this water can be held back, it can seep into the ground and recharge the groundwater supply. This has become a very popular method of conserving water especially in the urban areas. Rainwater harvesting essentially means collecting rainwater on the roofs of building and storing it underground for later use.
Not only does this recharging arrest groundwater depletion, it also raises the declining water table and can help augment water supply. Rainwater harvesting and artificial recharging are becoming very important issues. It is essential to stop the decline in groundwater levels, arrest sea-water ingress, i.e. prevent sea-water from moving landward, and conserve surface water run-off during the rainy season. Town planners and civic authority in many cities in India are introducing bylaws making rainwater harvesting compulsory in all new structures.
No water or sewage connection would be given if a new building did not have provisions for rainwater harvesting. Such rules should also be implemented in all the other cities to ensure a rise in the groundwater level. Realizing the importance of recharging groundwater, the CGWB (Central Ground Water Board) is taking steps to encourage it through rainwater harvesting in the capital and elsewhere. A number of government buildings have been asked to go in for water harvesting in Delhi and other cities of India.
All you need for a water harvesting system is rain, and a place to collect it! Typically, rain is collected on rooftops and other surfaces, and the water is carried down to where it can be used immediately or stored. You can direct water run-off from this surface to plants, trees or lawns or even to the aquifer. Some of the benefits of rainwater harvesting are as follows, Increases water availability, Checks the declining water table, Is environmentally friendly, Improves the quality of groundwater through the dilution of fluoride, nitrate, and salinity, Prevents soil erosion and flooding especially in urban areas.
Not only does this recharging arrest groundwater depletion, it also raises the declining water table and can help augment water supply. Rainwater harvesting and artificial recharging are becoming very important issues. It is essential to stop the decline in groundwater levels, arrest sea-water ingress, i.e. prevent sea-water from moving landward, and conserve surface water run-off during the rainy season. Town planners and civic authority in many cities in India are introducing bylaws making rainwater harvesting compulsory in all new structures.
No water or sewage connection would be given if a new building did not have provisions for rainwater harvesting. Such rules should also be implemented in all the other cities to ensure a rise in the groundwater level. Realizing the importance of recharging groundwater, the CGWB (Central Ground Water Board) is taking steps to encourage it through rainwater harvesting in the capital and elsewhere. A number of government buildings have been asked to go in for water harvesting in Delhi and other cities of India.
All you need for a water harvesting system is rain, and a place to collect it! Typically, rain is collected on rooftops and other surfaces, and the water is carried down to where it can be used immediately or stored. You can direct water run-off from this surface to plants, trees or lawns or even to the aquifer. Some of the benefits of rainwater harvesting are as follows, Increases water availability, Checks the declining water table, Is environmentally friendly, Improves the quality of groundwater through the dilution of fluoride, nitrate, and salinity, Prevents soil erosion and flooding especially in urban areas.
Water Conservation
Our ancient religious texts and epics give a good insight into the water storage and conservation systems that prevailed in those days. Over the years rising populations, growing industrialization, and expanding agriculture have pushed up the demand for water. Efforts have been made to collect water by building dams and reservoirs and digging wells; some countries have also tried to recycle and desalinate (remove salts) water. Water conservation has become the need of the day.
The idea of ground water recharging by harvesting rainwater is gaining importance in many cities. In the forests, water seeps gently into the ground as vegetation breaks the fall. This groundwater in turn feeds wells, lakes, and rivers. Protecting forests means protecting water 'catchments'. In ancient India, people believed that forests were the 'mothers' of rivers and worshipped the sources of these water bodies. The Indus Valley Civilization, that flourished along the banks of the river Indus and other parts of western and northern India about 5,000 years ago, had one of the most sophisticated urban water supply and sewage systems in the world.
The fact that the people were well acquainted with hygiene can be seen from the covered drains running beneath the streets of the ruins at both Mohenjodaro and Harappa. Another very good example is the well-planned city of Dholavira, on Khadir Bet, a low plateau in the Rann in Gujarat. One of the oldest water harvesting systems is found about 130 km from Pune along Naneghat in the Western Ghats. A large number of tanks were cut in the rocks to provide drinking water to tradesmen who used to travel along this ancient trade route. Each fort in the area had its own water harvesting and storage system in the form of rock-cut cisterns, ponds, tanks and wells that are still in use today.
A large number of forts like Raigad had tanks that supplied water. In ancient times, houses in parts of western Rajasthan were built so that each had a rooftop water harvesting system. Rainwater from these rooftops was directed into underground tanks. This system can be seen even today in all the forts, palaces and houses of the region. Underground baked earthen pipes and tunnels to maintain the flow of water and to transport it to distant places, are still functional at Burhanpur in Madhya Pradesh, Golkunda and Bijapur in Karnataka, and Aurangabad in Maharashtra.
The idea of ground water recharging by harvesting rainwater is gaining importance in many cities. In the forests, water seeps gently into the ground as vegetation breaks the fall. This groundwater in turn feeds wells, lakes, and rivers. Protecting forests means protecting water 'catchments'. In ancient India, people believed that forests were the 'mothers' of rivers and worshipped the sources of these water bodies. The Indus Valley Civilization, that flourished along the banks of the river Indus and other parts of western and northern India about 5,000 years ago, had one of the most sophisticated urban water supply and sewage systems in the world.
The fact that the people were well acquainted with hygiene can be seen from the covered drains running beneath the streets of the ruins at both Mohenjodaro and Harappa. Another very good example is the well-planned city of Dholavira, on Khadir Bet, a low plateau in the Rann in Gujarat. One of the oldest water harvesting systems is found about 130 km from Pune along Naneghat in the Western Ghats. A large number of tanks were cut in the rocks to provide drinking water to tradesmen who used to travel along this ancient trade route. Each fort in the area had its own water harvesting and storage system in the form of rock-cut cisterns, ponds, tanks and wells that are still in use today.
A large number of forts like Raigad had tanks that supplied water. In ancient times, houses in parts of western Rajasthan were built so that each had a rooftop water harvesting system. Rainwater from these rooftops was directed into underground tanks. This system can be seen even today in all the forts, palaces and houses of the region. Underground baked earthen pipes and tunnels to maintain the flow of water and to transport it to distant places, are still functional at Burhanpur in Madhya Pradesh, Golkunda and Bijapur in Karnataka, and Aurangabad in Maharashtra.
Eutrophication
When fresh water is artificially supplemented with nutrients, it results in an abnormal increase in the growth of water plants. This is known as eutrophication. The discharge of waste from industries, agriculture, and urban communities into water bodies generally stretches the biological capacities of aquatic systems. Chemical run-off from fields also adds nutrients to water. Excess nutrients cause the water body to become choked with organic substances and organisms. When organic matter exceeds the capacity of the micro-organisms in water that break down and recycle the organic matter, it encourages rapid growth, or blooms, of algae.
When they die, the remains of the algae add to the organic wastes already in the water; eventually, the water becomes deficient in oxygen. Anaerobic organisms (those that do not require oxygen to live) then attack the organic wastes, releasing gases such as methane and hydrogen sulphide, which are harmful to the oxygen-requiring (aerobic) forms of life. The result is a foul-smelling, waste-filled body of water. This has already occurred in such places as Lake Erie and the Baltic Sea, and is a growing problem in freshwater lakes all over India. Eutrophication can produce problems such as bad tastes and odours as well as green scum algae. Also the growth of rooted plants increases, which decreases the amount of oxygen in the deepest waters of the lake.
It also leads to the death of all forms of life in the water bodies. The amount of organic material that can rot in the sewage is measured by the biochemical oxygen demand. BOD is the amount of oxygen required by micro-organisms to decompose the organic substances in sewage. Therefore, the more organic material there is in the sewage, the higher the BOD. It is among the most important parameters for the design and operation of sewage treatment plants. BOD levels of industrial sewage may be many times that of domestic sewage.
Dissolved oxygen is an important factor that determines the quality of water in lakes and rivers. The higher the concentration of dissolved oxygen, the better the water quality. When sewage enters a lake or stream, micro-organisms begin to decompose the organic materials. Oxygen is consumed as micro-organisms use it in their metabolism. This can quickly deplete the available oxygen in the water. When the dissolved oxygen levels drop too low, many aquatic species perish. In fact, if the oxygen level drops to zero, the water will become septic. When organic compounds decompose without oxygen, it gives rise to the undesirable odours usually associated with septic or putrid conditions.
When they die, the remains of the algae add to the organic wastes already in the water; eventually, the water becomes deficient in oxygen. Anaerobic organisms (those that do not require oxygen to live) then attack the organic wastes, releasing gases such as methane and hydrogen sulphide, which are harmful to the oxygen-requiring (aerobic) forms of life. The result is a foul-smelling, waste-filled body of water. This has already occurred in such places as Lake Erie and the Baltic Sea, and is a growing problem in freshwater lakes all over India. Eutrophication can produce problems such as bad tastes and odours as well as green scum algae. Also the growth of rooted plants increases, which decreases the amount of oxygen in the deepest waters of the lake.
It also leads to the death of all forms of life in the water bodies. The amount of organic material that can rot in the sewage is measured by the biochemical oxygen demand. BOD is the amount of oxygen required by micro-organisms to decompose the organic substances in sewage. Therefore, the more organic material there is in the sewage, the higher the BOD. It is among the most important parameters for the design and operation of sewage treatment plants. BOD levels of industrial sewage may be many times that of domestic sewage.
Dissolved oxygen is an important factor that determines the quality of water in lakes and rivers. The higher the concentration of dissolved oxygen, the better the water quality. When sewage enters a lake or stream, micro-organisms begin to decompose the organic materials. Oxygen is consumed as micro-organisms use it in their metabolism. This can quickly deplete the available oxygen in the water. When the dissolved oxygen levels drop too low, many aquatic species perish. In fact, if the oxygen level drops to zero, the water will become septic. When organic compounds decompose without oxygen, it gives rise to the undesirable odours usually associated with septic or putrid conditions.
Facts about Water
75% of the earth's surface is covered with water, More than 97% of the earth's water is in its oceans, About 2% of the available drinking water is frozen leaving only 1% for drinking , The world's average rainfall is about 850 mm, Water regulates the Earth's temperature. It also regulates the temperature of the human body, carries nutrients and oxygen to cells, cushions joints, protects organs and tissues, and removes waste, 60% - 75% of the adult human body is water - 82% of blood is water; 70% of the brain and 90% of the lungs are made up of water.
Blood in animals and sap in plants is composed mainly of water, To cook 1 cup of rice you need 2 cups of water but to wash the pan in which it has been cooked you need 4-5 litres of water, A dripping tap can waste up to 6 litres of water in a day, More than half the creatures on the Earth are found under water, Life on earth probably originated in water, In the summer our bodies require about 2 litres of water daily. Here is the water content of some foods (approximate) - 95% in tomato, 91% in spinach, 91% in milk, 85% in apples and 80% in potatoes .
10% of the earth's surface is covered with ice There are more than one billion people particularly in North Africa and Western and South Asia, who lack access to a steady supply of clean water. Access to water and sanitation, so crucial to human well-being and development, has now become a priority for the international community. To underscore the need for immediate action, the United Nations has designated 2003 as the International Year of Freshwater. The importance given to water in ancient India is reflected in several hymns of the Vedas and epics and narratives from other valuable works such as the Arthasastra of Kautilya.
A large amount of water is wasted in agriculture, industry, and urban areas. It has been estimated that with available technologies and better operational practices, agricultural water demand could be cut by about 50%, and that in urban areas by about 33% without affecting the quality or economics of life. But most governments do not have adequate laws or regulations to protect their water systems. Due to the increase in population there has been a rise in the demand for food, space for housing, consumer products, etc., which has in turn resulted in increased industrialization, urbanization, and demands in agriculture thereby leading to both river and groundwater contamination.
Blood in animals and sap in plants is composed mainly of water, To cook 1 cup of rice you need 2 cups of water but to wash the pan in which it has been cooked you need 4-5 litres of water, A dripping tap can waste up to 6 litres of water in a day, More than half the creatures on the Earth are found under water, Life on earth probably originated in water, In the summer our bodies require about 2 litres of water daily. Here is the water content of some foods (approximate) - 95% in tomato, 91% in spinach, 91% in milk, 85% in apples and 80% in potatoes .
10% of the earth's surface is covered with ice There are more than one billion people particularly in North Africa and Western and South Asia, who lack access to a steady supply of clean water. Access to water and sanitation, so crucial to human well-being and development, has now become a priority for the international community. To underscore the need for immediate action, the United Nations has designated 2003 as the International Year of Freshwater. The importance given to water in ancient India is reflected in several hymns of the Vedas and epics and narratives from other valuable works such as the Arthasastra of Kautilya.
A large amount of water is wasted in agriculture, industry, and urban areas. It has been estimated that with available technologies and better operational practices, agricultural water demand could be cut by about 50%, and that in urban areas by about 33% without affecting the quality or economics of life. But most governments do not have adequate laws or regulations to protect their water systems. Due to the increase in population there has been a rise in the demand for food, space for housing, consumer products, etc., which has in turn resulted in increased industrialization, urbanization, and demands in agriculture thereby leading to both river and groundwater contamination.
Water
When Neil Armstrong saw the Earth from the Moon, it appeared blue! This is because water covers more than two-thirds of the Earth's surface. But fresh water represents less than 0.5% of the total water on Earth. The rest is either in the form of seawater or locked up in icecaps or the soil, which is why one often hears of water scarcity in many areas. Water is continuously moving around the earth and constantly changing its form. It evaporates from land and water bodies and is also produced by all forms of life on Earth.
This water vapour moves through the atmosphere, condenses to form clouds and precipitates as rain and snow. In time, the water returns to where it came from, and the process begins all over again. Although water is constantly moving, its total quantity on Earth's surface is constant. Water is found in three different forms - liquid, solid or gas, depending on the temperature but it constantly changes from one form to another. Changes in temperature will determine which of these forms predominates in a particular area.
Water is usually encountered in the liquid state, because this is its natural state when temperatures are between 0° C and 100° C. 'Fresh' or drinking water is found as groundwater in underground aquifers, and on the surface in ponds, lakes, and rivers. Seas and oceans account for 97% of all water on Earth; but their waters contain dissolved salts and are therefore unfit to drink. In regions of young volcanic activity, hot water emerges from the earth in hot springs (examples are Garampani in Assam and Badrinath in Uttaranchal). How does this phenomenon occur? Surface water percolates downward through the rocks below the Earth's surface to high-temperature regions surrounding a magma reservoir, either active, or recently solidified but still hot.
There the water is heated, becomes less dense, and rises back to the surface through fissures and cracks. Ice is the frozen form of water. It occurs when temperatures are below 0°C (32°F). For a given mass, ice occupies 9% more volume than water, which is why when water enters cracks in rocks and freezes it causes the rocks to crack and split. Being less dense than water, ice floats. This property of ice is vital to aquatic life in cold regions. As the temperature drops, ice forms a protective, insulating layer on the surfaces of streams, pools and other water bodies, allowing water to remain liquid in the layers beneath and life to survive. Glaciers, icebergs, and ice caps are all frozen water.
This water vapour moves through the atmosphere, condenses to form clouds and precipitates as rain and snow. In time, the water returns to where it came from, and the process begins all over again. Although water is constantly moving, its total quantity on Earth's surface is constant. Water is found in three different forms - liquid, solid or gas, depending on the temperature but it constantly changes from one form to another. Changes in temperature will determine which of these forms predominates in a particular area.
Water is usually encountered in the liquid state, because this is its natural state when temperatures are between 0° C and 100° C. 'Fresh' or drinking water is found as groundwater in underground aquifers, and on the surface in ponds, lakes, and rivers. Seas and oceans account for 97% of all water on Earth; but their waters contain dissolved salts and are therefore unfit to drink. In regions of young volcanic activity, hot water emerges from the earth in hot springs (examples are Garampani in Assam and Badrinath in Uttaranchal). How does this phenomenon occur? Surface water percolates downward through the rocks below the Earth's surface to high-temperature regions surrounding a magma reservoir, either active, or recently solidified but still hot.
There the water is heated, becomes less dense, and rises back to the surface through fissures and cracks. Ice is the frozen form of water. It occurs when temperatures are below 0°C (32°F). For a given mass, ice occupies 9% more volume than water, which is why when water enters cracks in rocks and freezes it causes the rocks to crack and split. Being less dense than water, ice floats. This property of ice is vital to aquatic life in cold regions. As the temperature drops, ice forms a protective, insulating layer on the surfaces of streams, pools and other water bodies, allowing water to remain liquid in the layers beneath and life to survive. Glaciers, icebergs, and ice caps are all frozen water.
Water Pollution
When toxic substances enter lakes, streams, rivers, oceans, and other water bodies, they get dissolved or lie suspended in water or get deposited on the bed. This results in the pollution of water whereby the quality of the water deteriorates, affecting aquatic ecosystems. Pollutants can also seep down and affect the groundwater deposits. Water pollution has many sources. The most polluting of them are the city sewage and industrial waste discharged into the rivers. The facilities to treat waste water are not adequate in any city in India.
Presently, only about 10% of the waste water generated is treated; the rest is discharged as it is into our water bodies. Due to this, pollutants enter groundwater, rivers, and other water bodies. Such water, which ultimately ends up in our households, is often highly contaminated and carries disease-causing microbes. Agricultural run-off, or the water from the fields that drains into rivers, is another major water pollutant as it contains fertilizers and pesticides. Domestic sewage refers to waste water that is discarded from households.
Also referred to as sanitary sewage, such water contains a wide variety of dissolved and suspended impurities. It amounts to a very small fraction of the sewage by weight. But it is large by volume and contains impurities such as organic materials and plant nutrients that tend to rot. The main organic materials are food and vegetable waste, plant nutrient come from chemical soaps, washing powders, etc. Domestic sewage is also very likely to contain disease-causing microbes. Thus, disposal of domestic waste water is a significant technical problem. Sewage generated from the urban areas in India has multiplied manifold since 1947.
Today, many people dump their garbage into streams, lakes, rivers, and seas, thus making water bodies the final resting place of cans, bottles, plastics, and other household products. The various substances that we use for keeping our houses clean add to water pollution as they contain harmful chemicals. In the past, people mostly used soaps made from animal and vegetable fat for all types of washing. But most of today’s cleaning products are synthetic detergents and come from the petrochemical industry. Most detergents and washing powders contain phosphates, which are used to soften the water among other things. These and other chemicals contained in washing powders affect the health of all forms of life in the water.
Presently, only about 10% of the waste water generated is treated; the rest is discharged as it is into our water bodies. Due to this, pollutants enter groundwater, rivers, and other water bodies. Such water, which ultimately ends up in our households, is often highly contaminated and carries disease-causing microbes. Agricultural run-off, or the water from the fields that drains into rivers, is another major water pollutant as it contains fertilizers and pesticides. Domestic sewage refers to waste water that is discarded from households.
Also referred to as sanitary sewage, such water contains a wide variety of dissolved and suspended impurities. It amounts to a very small fraction of the sewage by weight. But it is large by volume and contains impurities such as organic materials and plant nutrients that tend to rot. The main organic materials are food and vegetable waste, plant nutrient come from chemical soaps, washing powders, etc. Domestic sewage is also very likely to contain disease-causing microbes. Thus, disposal of domestic waste water is a significant technical problem. Sewage generated from the urban areas in India has multiplied manifold since 1947.
Today, many people dump their garbage into streams, lakes, rivers, and seas, thus making water bodies the final resting place of cans, bottles, plastics, and other household products. The various substances that we use for keeping our houses clean add to water pollution as they contain harmful chemicals. In the past, people mostly used soaps made from animal and vegetable fat for all types of washing. But most of today’s cleaning products are synthetic detergents and come from the petrochemical industry. Most detergents and washing powders contain phosphates, which are used to soften the water among other things. These and other chemicals contained in washing powders affect the health of all forms of life in the water.
Specific Air Pollutants
Some of these gases can seriously and adversely affect the health of the population and should be given due attention by the concerned authority. The gases mentioned below are mainly outdoor air pollutants but some of them can and do occur indoor depending on the source and the circumstances. Tobacco smoke. Tobacco smoke generates a wide range of harmful chemicals and is a major cause of ill health, as it is known to cause cancer, not only to the smoker but affecting passive smokers too.
It is well-known that smoking affects the passive smoker (the person who is in the vicinity of a smoker and is not himself/herself a smoker) ranging from burning sensation in the eyes or nose, and throat irritation, to cancer, bronchitis, severe asthma, and a decrease in lung function. Biological pollutants. These are mostly allergens that can cause asthma, hay fever, and other allergic diseases. Volatile organic compounds. Volatile compounds can cause irritation of the eye, nose and throat. In severe cases there may be headaches, nausea, and loss of coordination. In the longer run, some of them are suspected to cause damage to the liver and other parts of the body.
Formaldehyde. Exposure causes irritation to the eyes, nose and may cause allergies in some people. Lead. Prolonged exposure can cause damage to the nervous system, digestive problems, and in some cases cause cancer. It is especially hazardous to small children. Radon. A radioactive gas that can accumulate inside the house, it originates from the rocks and soil under the house and its level is dominated by the outdoor air and also to some extent the other gases being emitted indoors. Exposure to this gas increases the risk of lung cancer.
Ozone, Exposure to this gas makes our eyes itch, burn, and water and it has also been associated with increase in respiratory disorders such as asthma. It lowers our resistance to colds and pneumonia. Oxides of nitrogen. This gas can make children susceptible to respiratory diseases in the winters.Carbon monoxide. CO (carbon monoxide) combines with haemoglobin to lessen the amount of oxygen that enters our blood through our lungs. The binding with other haeme proteins causes changes in the function of the affected organs such as the brain and the cardiovascular system, and also the developing foetus.
It can impair our concentration, slow our reflexes, and make us confused and sleepy. Sulphur dioxide. SO2 (sulphur dioxide) in the air is caused due to the rise in combustion of fossil fuels. It can oxidize and form sulphuric acid mist. SO2 in the air leads to diseases of the lung and other lung disorders such as wheezing and shortness of breath. Long-term effects are more difficult to ascertain as SO2 exposure is often combined with that of SPM. SPM (suspended particulate matter). Suspended matter consists of dust, fumes, mist and smoke. The main chemical component of SPM that is of major concern is lead, others being nickel, arsenic, and those present in diesel exhaust. These particles when breathed in, lodge in our lung tissues and cause lung damage and respiratory problems. The importance of SPM as a major pollutant needs special emphasis as a) it affects more people globally than any other pollutant on a continuing basis; b) there is more monitoring data available on this than any other pollutant; and c) more epidemiological evidence has been collected on the exposure to this than to any other pollutant.
Impact Of Air Pollution
The magnitude of the London fog of 1952, which affected such a large number of people, was the first incident that made people aware of the damage done to the atmosphere due to industrialization. The SPM levels increased manifold and resulted in over 4000 deaths. Indoor air pollution can be particularly hazardous to health as it is released in close proximity to people. It is stated that a pollutant released indoors is many times more likely to reach the lung than that released outdoors.
In the developing countries a fairly large portion of the population is dependent on biomass for their energy requirements. These include wood, charcoal, agricultural residue, and animal waste. Open fires used for cooking and heating are commonly found in the household both in the rural and the urban areas. The stove is often at floor level, adding to the risk of accident and the hygiene factor. In addition, they are often not fitted with a chimney to remove the pollutants. In such households the children and women are most likely to be affected, as they are the group that spends more time indoors.
The main pollutant in this environment is the SPM. In fact, death due to indoor air pollution, mainly particulate matters, in the rural areas of India are one of the highest in the world. Many of the deaths are due to acute respiratory infections in children; others are due to cardiovascular diseases, lung cancer, and chronic respiratory diseases in adults. If emissions are high and ventilation is poor, household use of coal and biomass can severely affect the indoor air quality. Pollutant emissions per meal are also very high compared to those of other fuels.
Household use of fossil fuel is also fairly common in the developing countries, particularly coal—both bituminous and lignite. These are particularly damaging as they burn inefficiently and emit considerable quantities of air pollutants. If emissions are high and ventilation poor, then the exposure levels to the gases emitted are far higher. The most harmful of the gases and agents that are emitted are particulate matter, carbon dioxide, polycyclic organic matter, and formaldehyde. The indoor concentrations of these are far higher than the acceptable levels and is cause for concern in rural areas.
In the developing countries a fairly large portion of the population is dependent on biomass for their energy requirements. These include wood, charcoal, agricultural residue, and animal waste. Open fires used for cooking and heating are commonly found in the household both in the rural and the urban areas. The stove is often at floor level, adding to the risk of accident and the hygiene factor. In addition, they are often not fitted with a chimney to remove the pollutants. In such households the children and women are most likely to be affected, as they are the group that spends more time indoors.
The main pollutant in this environment is the SPM. In fact, death due to indoor air pollution, mainly particulate matters, in the rural areas of India are one of the highest in the world. Many of the deaths are due to acute respiratory infections in children; others are due to cardiovascular diseases, lung cancer, and chronic respiratory diseases in adults. If emissions are high and ventilation is poor, household use of coal and biomass can severely affect the indoor air quality. Pollutant emissions per meal are also very high compared to those of other fuels.
Household use of fossil fuel is also fairly common in the developing countries, particularly coal—both bituminous and lignite. These are particularly damaging as they burn inefficiently and emit considerable quantities of air pollutants. If emissions are high and ventilation poor, then the exposure levels to the gases emitted are far higher. The most harmful of the gases and agents that are emitted are particulate matter, carbon dioxide, polycyclic organic matter, and formaldehyde. The indoor concentrations of these are far higher than the acceptable levels and is cause for concern in rural areas.
Health Impacts of Air Pollution
Since the onset of the industrial revolution, there has been a steady change in the composition of the atmosphere mainly due to the combustion of fossil fuels used for the generation of energy and transportation. Air pollution is a major environmental health problem affecting the developing and the developed countries alike. The effects of air pollution on health are very complex as there are many different sources and their individual effects vary from one to the other.
It is not only the ambient air quality in the cities but also the indoor air quality in the rural and the urban areas that are causing concern. In fact in the developing world the highest air pollution exposures occur in the indoor environment. Air pollutants that are inhaled have serious impact on human health affecting the lungs and the respiratory system; they are also taken up by the blood and pumped all round the body. These pollutants are also deposited on soil, plants, and in the water, further contributing to human exposure.
As you read on you can learn about health impacts of specific air pollutants. Air pollutants consist of gaseous pollutants, odours, and SPM, (suspended particulate matter) such as dust, fumes, mist, and smoke. The concentration of these in and near the urban areas causes severe pollution to the surroundings. The largest sources of human-created air pollution are energy generation, transportation, and industries that use a great deal of energy sources. Depending on their source and interactions with other components of the air, they can have different chemical compositions and health impacts.
Since these pollutants are generally concentrated in and around urban areas, the outdoor urban pollution levels are far higher than in the rural areas. Fires are another major source of air pollution and can lead to severe problems if the smoke is inhaled for a period of time. These fires can either be forest fires, oil well fires, burning of leaves in the backyard or as in the case of rural areas, large-scale burning of agricultural waste. Other sources include industries and power plants located in these areas.
It is not only the ambient air quality in the cities but also the indoor air quality in the rural and the urban areas that are causing concern. In fact in the developing world the highest air pollution exposures occur in the indoor environment. Air pollutants that are inhaled have serious impact on human health affecting the lungs and the respiratory system; they are also taken up by the blood and pumped all round the body. These pollutants are also deposited on soil, plants, and in the water, further contributing to human exposure.
As you read on you can learn about health impacts of specific air pollutants. Air pollutants consist of gaseous pollutants, odours, and SPM, (suspended particulate matter) such as dust, fumes, mist, and smoke. The concentration of these in and near the urban areas causes severe pollution to the surroundings. The largest sources of human-created air pollution are energy generation, transportation, and industries that use a great deal of energy sources. Depending on their source and interactions with other components of the air, they can have different chemical compositions and health impacts.
Since these pollutants are generally concentrated in and around urban areas, the outdoor urban pollution levels are far higher than in the rural areas. Fires are another major source of air pollution and can lead to severe problems if the smoke is inhaled for a period of time. These fires can either be forest fires, oil well fires, burning of leaves in the backyard or as in the case of rural areas, large-scale burning of agricultural waste. Other sources include industries and power plants located in these areas.
Effects of Smog
The effects of smog on human health were evident, particularly when smog persisted for several days. Many people suffered respiratory problems and increased deaths were recorded, notably those relating to bronchial causes. A haze of dense harmful smog would often cover the city of London. The first smog-related deaths were recorded in London in 1873, when it killed 500 people. In 1880, the toll was 2000. London had one of its worst experiences with smog in December 1892. It lasted for three days and resulted in about 1000 deaths.
London became quite notorious for its smog. By the end of the 19th century, many people visited London to see the fog. Despite gradual improvements in air quality during the 20th century, another major smog occurred in London in December 1952. The Great London Smog lasted for five days and resulted in about 4000 more deaths than usual. In response to the Great London Smog, the government passed its first Clean Air Act in 1956, which aimed to control domestic sources of smoke pollution by introducing smokeless zones.
In addition, the introduction of cleaner coals led to a reduction in sulphur dioxide pollution. In the 1940s, severe smog began covering the city of Los Angeles in the USA. Relatively little was done to control any type of pollution or to promote environmental protection until the middle of the 20th century. Today, smoke and sulphur dioxide pollution in cities is much lower than in the past, as a result of legislation to control pollution emissions and cleaner emission technology. Ground-level ozone is formed through a complex reaction involving hydrocarbons, nitrogen oxides, and sunlight.
Ground-level ozone is especially harmful for seniors, children, asthmatics, and people with heart and lung conditions. It aggravates respiratory symptoms and further impairs the ability of these individuals to perform normal activities. It can inflame breathing passages, decreasing the lung's working capacity, and causing shortness of breath, pain when inhaling deeply, wheezing, and coughing. It can cause eye and nose irritation and dry out the protective membranes of the nose and throat and interfere with the body's ability to fight infection, increasing susceptibility to illness.
London became quite notorious for its smog. By the end of the 19th century, many people visited London to see the fog. Despite gradual improvements in air quality during the 20th century, another major smog occurred in London in December 1952. The Great London Smog lasted for five days and resulted in about 4000 more deaths than usual. In response to the Great London Smog, the government passed its first Clean Air Act in 1956, which aimed to control domestic sources of smoke pollution by introducing smokeless zones.
In addition, the introduction of cleaner coals led to a reduction in sulphur dioxide pollution. In the 1940s, severe smog began covering the city of Los Angeles in the USA. Relatively little was done to control any type of pollution or to promote environmental protection until the middle of the 20th century. Today, smoke and sulphur dioxide pollution in cities is much lower than in the past, as a result of legislation to control pollution emissions and cleaner emission technology. Ground-level ozone is formed through a complex reaction involving hydrocarbons, nitrogen oxides, and sunlight.
Ground-level ozone is especially harmful for seniors, children, asthmatics, and people with heart and lung conditions. It aggravates respiratory symptoms and further impairs the ability of these individuals to perform normal activities. It can inflame breathing passages, decreasing the lung's working capacity, and causing shortness of breath, pain when inhaling deeply, wheezing, and coughing. It can cause eye and nose irritation and dry out the protective membranes of the nose and throat and interfere with the body's ability to fight infection, increasing susceptibility to illness.
Smog
The term smog was first used in 1905 by Dr H A Des Voeux to describe the conditions of fog that had soot or smoke in it. Smog is a combination of various gases with water vapour and dust. A large part of the gases that form smog is produced when fuels are burnt. Smog forms when heat and sunlight react with these gases and fine particles in the air. Smog can affect outlying suburbs and rural areas as well as big cities. Its occurrences are often linked to heavy traffic, high temperatures, and calm winds.
During the winter, wind speeds are low and cause the smoke and fog to stagnate; hence pollution levels can increase near ground level. This keeps the pollution close to the ground, right where people are breathing. It hampers visibility and harms the environment. Heavy smog is greatly decreases ultraviolet radiation. In fact, in the early part of the 20th century, heavy smog in some parts of Europe resulted in a decrease in the production of natural vitamin D leading to a rise in the cases of rickets.
Smog causes a misty haze similar to fog, but very different in composition. In fact the word smog has been coined from a combination of the words fog and smoke. Smog refers to hazy air that causes difficult breathing conditions. The most harmful components of smog are ground-level ozone and fine airborne particles. Ground-level ozone forms when pollutants released from gasoline and diesel-powered vehicles and oil-based solvents react with heat and sunlight. It is harmful to humans, animals, and plants.
The industrial revolution in the 19th century saw the beginning of air pollution in Europe on a large scale and the presence of smog mainly in Britain. The industries and the households relied heavily on coal for heating and cooking. Due to the burning of coal for heat during the winter months, emissions of smoke and sulphur dioxide were much greater in urban areas than they were during the summer months. Smoke particles trapped in the fog gave it a yellow/black colour and this smog often settled over cities for many days.
During the winter, wind speeds are low and cause the smoke and fog to stagnate; hence pollution levels can increase near ground level. This keeps the pollution close to the ground, right where people are breathing. It hampers visibility and harms the environment. Heavy smog is greatly decreases ultraviolet radiation. In fact, in the early part of the 20th century, heavy smog in some parts of Europe resulted in a decrease in the production of natural vitamin D leading to a rise in the cases of rickets.
Smog causes a misty haze similar to fog, but very different in composition. In fact the word smog has been coined from a combination of the words fog and smoke. Smog refers to hazy air that causes difficult breathing conditions. The most harmful components of smog are ground-level ozone and fine airborne particles. Ground-level ozone forms when pollutants released from gasoline and diesel-powered vehicles and oil-based solvents react with heat and sunlight. It is harmful to humans, animals, and plants.
The industrial revolution in the 19th century saw the beginning of air pollution in Europe on a large scale and the presence of smog mainly in Britain. The industries and the households relied heavily on coal for heating and cooking. Due to the burning of coal for heat during the winter months, emissions of smoke and sulphur dioxide were much greater in urban areas than they were during the summer months. Smoke particles trapped in the fog gave it a yellow/black colour and this smog often settled over cities for many days.
Acid Rain
Another effect of air pollution is acid rain. The phenomenon occurs when sulphur dioxide and nitrogen oxides from the burning of fossil fuels such as, petrol, diesel, and coal combine with water vapour in the atmosphere and fall as rain, snow or fog. These gases can also be emitted from natural sources like volcanoes. Acid rain causes extensive damage to water, forest, soil resources and even human health. Many lakes and streams have been contaminated and this has led to the disappearance of some species of fish in Europe, USA and Canada as also extensive damage to forests and other forms of life.
It is said that it can corrode buildings and be hazardous to human health. Because the contaminants are carried long distances, the sources of acid rain are difficult to pinpoint and hence difficult to control. For example, the acid rain that may have damaged some forest in Canada could have originated in the industrial areas of USA. In fact, this has created disagreements between Canada and the United States and among European countries over the causes of and solutions to the problem of acid rain.
The international scope of the problem has led to the signing of international agreements on the limitation of sulphur and nitrogen oxide emissions. The Atmospheric Science Division evaluates the impact of acidifying emission control programs by analyzing the changes in acid deposition at regionally-representative monitoring sites in the Atlantic Region and determining which areas are exposed to continuing acidification because deposition levels exceed the environmental damage level.
The fight against acid rain is not over yet. Acid deposition exceeds critical loads across large portions of eastern Canada, including most of New Brunswick and Nova Scotia. As a result, acidification in these areas will continue, the biodiversity of aquatic ecosystems will remain under threat, and more damage to forest health and productivity will occur unless further deep cuts in sulphur dioxide and nitrogen oxide emissions in Canada and the United States are implemented.
It is said that it can corrode buildings and be hazardous to human health. Because the contaminants are carried long distances, the sources of acid rain are difficult to pinpoint and hence difficult to control. For example, the acid rain that may have damaged some forest in Canada could have originated in the industrial areas of USA. In fact, this has created disagreements between Canada and the United States and among European countries over the causes of and solutions to the problem of acid rain.
The international scope of the problem has led to the signing of international agreements on the limitation of sulphur and nitrogen oxide emissions. The Atmospheric Science Division evaluates the impact of acidifying emission control programs by analyzing the changes in acid deposition at regionally-representative monitoring sites in the Atlantic Region and determining which areas are exposed to continuing acidification because deposition levels exceed the environmental damage level.
The fight against acid rain is not over yet. Acid deposition exceeds critical loads across large portions of eastern Canada, including most of New Brunswick and Nova Scotia. As a result, acidification in these areas will continue, the biodiversity of aquatic ecosystems will remain under threat, and more damage to forest health and productivity will occur unless further deep cuts in sulphur dioxide and nitrogen oxide emissions in Canada and the United States are implemented.
How to Prevent Pollution
The task of cleaning up air pollution, though difficult, is not believed to be impossible. The shift to less polluting forms of power generation, such as solar energy, wind energy, geothermal, tidal and other forms of renewable energy in place of fossil fuel can be used for controlling pollution. The example of London, as well as of other cities, has shown that major improvements in air quality can be achieved in 10 years or less. Many cities in India now have pollution control checks for vehicles.
Cars are being fitted with catalytic converters and unleaded petrol is being used. There is an attempt to keep a check on polluting industrial units by the judiciary. Cars that use CNG have also been introduced. You can also contribute to reducing air pollution to some extent. One of the first things you can start doing is to conserve energy. Walk or ride a bicycle to the market or to your friend’s house. Take a bus to school or organize a carpool. See to it that the use of aerosols is reduced in your house.
Make sure that your father or mother gets a pollution check of the car done at regular intervals and that the car is well maintained. Trees give out oxygen and take in carbon dioxide and thereby clean the air around us. It is therefore our duty to take care of them. Look after the trees in your neighborhood, along with your friends, begin a tree watch similar to a neighborhood watch. See to it that trees in your area are looked after. Plant more trees and tend to them too. Switch off the lights and fans each time you leave a room.
During the day, use only the required number of lights. At home, during hot summer months when you tend to use an airconditioner or a cooler or a heater on very cold winter days, learn to share the room with your brother or sister when you are studying, watching the television, etc. Electrostatic precipitators An electrostatic precipitator (ESP), or electrostatic air cleaner is a particulate collection device that removes particles from a flowing gas (such as air) using the force of an induced electrostatic charge. Electrostatic precipitators are highly efficient filtration devices that minimally impede the flow of gases through the device, and can easily remove fine particulate matter such as dust and smoke from the air stream.
Cars are being fitted with catalytic converters and unleaded petrol is being used. There is an attempt to keep a check on polluting industrial units by the judiciary. Cars that use CNG have also been introduced. You can also contribute to reducing air pollution to some extent. One of the first things you can start doing is to conserve energy. Walk or ride a bicycle to the market or to your friend’s house. Take a bus to school or organize a carpool. See to it that the use of aerosols is reduced in your house.
Make sure that your father or mother gets a pollution check of the car done at regular intervals and that the car is well maintained. Trees give out oxygen and take in carbon dioxide and thereby clean the air around us. It is therefore our duty to take care of them. Look after the trees in your neighborhood, along with your friends, begin a tree watch similar to a neighborhood watch. See to it that trees in your area are looked after. Plant more trees and tend to them too. Switch off the lights and fans each time you leave a room.
During the day, use only the required number of lights. At home, during hot summer months when you tend to use an airconditioner or a cooler or a heater on very cold winter days, learn to share the room with your brother or sister when you are studying, watching the television, etc. Electrostatic precipitators An electrostatic precipitator (ESP), or electrostatic air cleaner is a particulate collection device that removes particles from a flowing gas (such as air) using the force of an induced electrostatic charge. Electrostatic precipitators are highly efficient filtration devices that minimally impede the flow of gases through the device, and can easily remove fine particulate matter such as dust and smoke from the air stream.
Major Pollutants of Air
One of the formal definitions of air pollution is as follows – ‘The presence in the atmosphere of one or more contaminants in such quality and for such duration as is injurious, or tends to be injurious, to human health or welfare, animal or plant life.’ It is the contamination of air by the discharge of harmful substances. Air pollution can cause health problems and it can also damage the environment and property. It has caused thinning of the protective ozone layer of the atmosphere, which is leading to climate change.
Modernisation and progress have led to air getting more and more polluted over the years. Industries, vehicles, increase in the population, and urbanization are some of the major factors responsible for air pollution. The following industries are among those that emit a great deal of pollutants into the air: thermal power plants, cement, steel, refineries, petro chemicals, and mines. Air pollution results from a variety of causes, not all of which are within human control. Dust storms in desert areas and smoke from forest fires and grass fires contribute to chemical and particulate pollution of the air.
The source of pollution may be in one country but the impact of pollution may be felt elsewhere. The discovery of pesticides in Antarctica, where they have never been used, suggests the extent to which aerial transport can carry pollutants from one place to another. Probably the most important natural source of air pollution is volcanic activity, which at times pours great amounts of ash and toxic fumes into the atmosphere. The eruptions of such volcanoes as Krakatoa in Indonesia, Mt. St. Helens in Washington, USA and Katmai in Alaska, USA, have been related to measurable climatic changes.
Carbon monoxide (CO)is a colourless, odourless gas that is produced by the incomplete burning of carbon-based fuels including petrol, diesel, and wood. It is also produced from the combustion of natural and synthetic products such as cigarettes. It lowers the amount of oxygen that enters our blood . It can slow our reflexes and make us confused and sleepy. Chloroflorocarbons (CFC) are gases that are released mainly from air-conditioning systems and refrigeration. When released into the air, CFCs rise to the stratosphere, where they come in contact with few other gases, which leads to a reduction of the ozone layer that protects the earth from the harmful ultraviolet rays of the sun. Leadis present in petrol, diesel, lead batteries, paints, hair dye products, etc. Lead affects children in particular. It can cause nervous system damage and digestive problems and, in some cases, cause cancer.
Modernisation and progress have led to air getting more and more polluted over the years. Industries, vehicles, increase in the population, and urbanization are some of the major factors responsible for air pollution. The following industries are among those that emit a great deal of pollutants into the air: thermal power plants, cement, steel, refineries, petro chemicals, and mines. Air pollution results from a variety of causes, not all of which are within human control. Dust storms in desert areas and smoke from forest fires and grass fires contribute to chemical and particulate pollution of the air.
The source of pollution may be in one country but the impact of pollution may be felt elsewhere. The discovery of pesticides in Antarctica, where they have never been used, suggests the extent to which aerial transport can carry pollutants from one place to another. Probably the most important natural source of air pollution is volcanic activity, which at times pours great amounts of ash and toxic fumes into the atmosphere. The eruptions of such volcanoes as Krakatoa in Indonesia, Mt. St. Helens in Washington, USA and Katmai in Alaska, USA, have been related to measurable climatic changes.
Carbon monoxide (CO)is a colourless, odourless gas that is produced by the incomplete burning of carbon-based fuels including petrol, diesel, and wood. It is also produced from the combustion of natural and synthetic products such as cigarettes. It lowers the amount of oxygen that enters our blood . It can slow our reflexes and make us confused and sleepy. Chloroflorocarbons (CFC) are gases that are released mainly from air-conditioning systems and refrigeration. When released into the air, CFCs rise to the stratosphere, where they come in contact with few other gases, which leads to a reduction of the ozone layer that protects the earth from the harmful ultraviolet rays of the sun. Leadis present in petrol, diesel, lead batteries, paints, hair dye products, etc. Lead affects children in particular. It can cause nervous system damage and digestive problems and, in some cases, cause cancer.
Indoor Air Pollution
It refers to the physical, chemical, and biological characteristics of air in the indoor environment within a home, building, or an institution or commercial facility. Indoor air pollution is a concern in the developed countries, where energy efficiency improvements sometimes make houses relatively airtight, reducing ventilation and raising pollutant levels. Indoor air problems can be subtle and do not always produce easily recognized impacts on health. Different conditions are responsible for indoor air pollution in the rural areas and the urban areas.
In the developing countries, it is the rural areas that face the greatest threat from indoor pollution, where some 3.5 billion people continue to rely on traditional fuels such as firewood, charcoal, and cowdung for cooking and heating. Concentrations of indoor pollutants in households that burn traditional fuels are alarming. Burning such fuels produces large amount of smoke and other air pollutants in the confined space of the home, resulting in high exposure. Women and children are the groups most vulnerable as they spend more time indoors and are exposed to the smoke.
In 1992, the World Bank designated indoor air pollution in the developing countries as one of the four most critical global environmental problems. Daily averages of pollutant level emitted indoors often exceed current WHO guidelines and acceptable levels. Although many hundreds of separate chemical agents have been identified in the smoke from biofuels, the four most serious pollutants are particulates, carbon monoxide, polycyclic organic matter, and formaldehyde. Unfortunately, little monitoring has been done in rural and poor urban indoor environments in a manner that is statistically rigorous.
In urban areas, exposure to indoor air pollution has increased due to a variety of reasons, including the construction of more tightly sealed buildings, reduced ventilation, the use of synthetic materials for building and furnishing and the use of chemical products, pesticides, and household care products. Indoor air pollution can begin within the building or be drawn in from outdoors. Other than nitrogen dioxide, carbon monoxide, and lead, there are a number of other pollutants that affect the air quality in an enclosed space.
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