Normal rainwater has a pH of 5.6 because the carbon dioxide in the air combines with water to to give a weak solution of carbonic acid.
When fossil fuels burn, sulfur dioxide and nitrogen oxides combine with water to produce sulfuric and nitric acids, causing acid rain.
Impact on Lakes
Acid rain in Canada and New England has caused hundreds of lakes to be devoid of fish, and in some cases, any life at all.
Impact on Forest
In New England and the southern Appalachians, millions of acres of high elevation forests have been devastated (by acid rain.
Sulfur dioxide and nitrogen oxides, the main precursors of acid rain, have been steadily decreasing in the United States due to clean air legislation and strict emission limits.
Impact on Humans and Structures
Inhaling dry sulfate and nitrate particles appears to increase the occurrence of respiratory illnesses, such as asthma. Buildings and monuments made of limestone and marble break down when exposed to acid rain. The paint on homes and automobiles is likewise degraded.
Damage is decreased because of efforts to reduce chemicals that contribute to acid rain.
Conclusions from article and graph.
Acid rain emissions are trending downward.
Using less fossil fuels and capturing or converting the pollutants might help reduce sulfur dioxide and nitrogen oxide.
Acid rain converts mercury in lake bottom sediments to toxic methyl mercury. Reducing acid rain emissions is essential to keep mercury from accumulating in fish.