Most of the data available on impacts of acidic precipitation are derived from studies on the effects of increased acidity on aquatic organisms. The chemical composition of lakes is determined largely by the composition of influents from precipitation and watershed drainage.

Acid rain causes a decrease in pH level. Acid rain has also effect on fish. In acidified lakes, the fish mortality increases. A sudden short change in

Moreover, acid rain has important effects on human health. Mobility of metallic compounds in soil is increased at low pH levels. Therefore, there is a potential impact of acidic precipitation on human health. In fact, we can be contaminated by eating fish and drinking water supplies by these metallic compounds. But some studies have proved that the level of metallic species in these lakes is well below public health drinking water standards.

pH can kill fishes. It often occurs in early spring when snow melt releases acidic constituents accumulated during the winter. A gradual decrease in pH with time is a second mechanism of the increase of fish mortality. Field observations and laboratory experiments have showed that prolonged acidity interferes with fish reproduction. That is to say, there is a decrease in fish population density and a modification of the size and age of

Some common words found in the essay are:
, Ca2+ Acidic, acid rain, acidic precipitation, terrestrial ecosystems, human health, effects vegetation, dry deposition, fish mortality, metallic compounds, drinking water, decrease ph,
Approximate Word count = 592
Approximate Pages = 2 (250 words per page double spaced)