27 Oct 2014
The sky was wearing a blue coat, but humans are forced to give it on a blue coat; the earth had clear blood, but humans make it black, dirty and stinking, and his green coat was torn to rags. Did you hear that the sky is crying, and the earth is crying? All this is caused by acid rain. Acid rain exists in so many countries that become a common problem. So, what is acid rain? How does acid rain form? How does it affect the environment and our lives? We should pay more attention to it, because we are facing a huge crisis. Acid rain is a rain or any other form of precipitation that is unusually acidic, meaning that it possesses elevated levels of hydrogen ions (low pH). It can have harmful effects on plants, aquatic animals and infrastructure. Acid rain is caused by emissions of sulfur dioxide and nitrogen oxide, which react with the water molecules in the atmosphere to produce acids (en.wikipedia.org). However, acid rain doesn’t always have to be rain. It has many different forms. It can be in liquid forms, such as rain, snow, sleet, ice, fog, hail, etc.(U.S. Environmental Protection Agency). Pretty much any form water takes, acidic particles can contaminate it. In the dry form, dust, soot, and smoke with acidic particles falls onto the earth. When it rains, the acidic particles are mixed with the water, making it more acidic, and carried out into streams, lakes and other bodies of water (Buzzle). This also happens with acid snow and acid ice. The snow or ice eventually melts and then runs into streams, then into lakes or oceans, making them more acidic (virtual chembook). The formation of acid rain is caused by atmospheric pollution, such as burning of high sulfur coal and high sulfur diesel fuel. So, human activities are the primary cause of acid rain. Environmental pollution led to the formation of acid rain. At the same time, the acid rain has led to more serious environmental problems. Acid rain affects plants, animals, water, environment, even our lives:
The effects of acid rain are most clearly seen in the aquatic, or water, environments, such as streams, lakes, and marshes. Acid rain flows to streams, lakes, and marshes after falling in forests, fields, buildings, and roads. Acid rain also falls directly on aquatic habitats.
Most lakes and streams have a pH between 6 and 8. However, some lakes are naturally acidic even without the effects of acid rain. Lakes and streams become acidic (pH value goes down) when the water itself and its surrounding soil cannot buffer the acid rain enough to neutralize it. The adjacent chart shows that not all fish, shellfish, or their food insects can tolerate the same amount of acid.
Generally, the young of most species are more sensitive than adults. Frogs may tolerate relatively high levels of acidity, but if they eat insects like the mayfly, they may be affected because part of their food supply may disappear. As lakes and streams become more acidic, the numbers and types of fish and other aquatic plants and animals that live in these waters decrease. Some types of plants and animals are able to tolerate acidic waters. Others, however, are acid-sensitive and will be lost as the pH declines. At pH 5, most fish eggs cannot hatch. At lower pH levels, some