Acid rain reaches the earth in five different forms: rain, snow, hail, sleet, or fog. There are also dry acidic particles that fall from the atmosphere.
Most people do not think that acid rain is a big deal, but it is. There have been laws passed to help control this issue, but it has not helped the United States as much as it should have. In this report I will explain controversies in the past over acid rain and I will say a little bit about what is going on in the present.
In the 1980"s acid rain was a major environmental issue. Environmentalists believed that acid rain was poisoning lakes and killing fish in North America. Because the political debate was so fierce, and the scientific process was so acrimonious, Congress created what was then the country"s biggest environmental research project which consumed half a billion dollars in 10 years. Following this research project, Congress amended the Clean Air Act in 1990, which required polluters, mainly electric power companies, to reduce their emission of sulphur dioxide. After this act, the problem seemed to be solved.
Now we have come to realize that acid rain has not at all disappeared. In many lakes across North America the water is less acidic, but there is no sign of recovery across the northeastern and midwestern United States-and there may not be for decades. Gene Likens, an ecologist at the Institute of Ecosystem Studies in Millbrook, N.Y. quotes, " The problem is complex, and it has not gone away."
Here is a list of some of the effects of acid rain in aquatic ecosystems:
v As the pH approaches 6.0, crustaceans, insects, and some plankton species begin to disappear.
v As pH approaches 5.0, major changes in the makeup of the plankton community occur, less desirable species of mosses and plankton may begin to invade, and the progressive loss of some fish populations is likely, with the more highly valued species being generally the least tolerant of acidity.
v Below pH of 5.0, the water is largely devoid of fish, the bottom is covered with undecayed material, and mosses may dominate the areas near the shore.
v Terrestrial animals dependent on aquatic ecosystems are also affected. Waterfowl, for example, depend on aquatic organisms for nourishment and nutrients. As these food sources are reduced or eliminated, the quality of habitat declines and the reproductive success of the birds is affected.
When a lake is too acidic, many fish, insects, amphibians, birds, plants, and etc. die. Eventually every form of life will die. Because the young fish are weaker than the fully-grown ones, a whole generation of young fish can die if the water is too acidic. Even if the fish were to survive the water, they may die because their food supply has decreased drastically because of the acid rain. Birds also suffer from this problem. They depend on the lakes for food, and when the lakes and fish are poisoned or dead, therefore the birds goes hungry.
Aquatic systems are not the only things that are affected by acid rain. Humans, plants, forests, and a whole bunch if other things are too. Acid rain can harm us (humans) in several ways:
v If the food we eat, the water we drink, and the air we breathe has come in contact with acid deposition, it can cause health problems for us.
v Studies have shown that there is a link between acid rain and respiratory problems in sensitive populations such as children and asthmatics.
v Also, acid rain can increase the levels of toxic metals such as aluminum, copper, and mercury in untreated drinking water supplies.
Plants can be harmed by acid rain in many ways also. For example, it can alter the
protective waxy surface of leaves, lowering disease resistance. Here are a few more examples:
v It may inhibit plant germination and reproduction.
v It accelerates soil weathering and removal of nutrients.
v It makes some toxic elements, such as aluminum, more soluble. High aluminum concentrations in the soil can prevent the uptake and use of nutrients by plants.
Its effects on animals are hard to assess. As a result of pollution-induced alteration of habitat or food resources, acid deposition may cause population decline through stress and lower reproductive success.
Acid rain affects forests and soils. When sulphuric acid falls onto the earth, nutrients present in the soil are washed away. Aluminum, which is present in the soil, is released and this element can be absorbed into the roots of trees and plants. As a result, the trees and plants are starved to death as they are deprived of their vital nutrients such as calcium and magnesium. The needles of some trees will turn yellow because of this; eventually they will fall off. Besides just killing the trees and plants, they also, acid rain also makes them grow when they don"t have the proper nutrients. Also, trees are forced to grow well into late autumn when it is actually time for them to prepare for severe frosts in the winter.
Man-made objects are also harmed. Rust can be formed on metal and statues, buildings, graves, and many other things can be ruined because of acid rain. Acid rain wears down rock structures down gradually, and can be devastating over a long period of time, sometimes causing bridges to collapse or become unstable.
In conclusion, acid rain may not sound all that harmful, but it really is and it is not a subject to be taken lightly. There are some things that you can do to reduce the acidity in acid rain, so maybe this report will change your mind and make you think!