Acidification indicates the presence of acid in soil, rainfall and waterways such as lakes
and rivers. Acidification is caused by the presence of oxides in the air which react with
atmospheric water to form acids. The acids fall to the ground as
href="http://en.wikipedia.org/wiki/Acid_rain">acid rain or snow.
href="/graph/env_pol_nit_oxi_per_cap">nitrogen oxides are the greatest contributors to
acidification. About half of all sulfur oxides and most nitrogen oxides enter the atmosphere
from natural sources, however human activities such as electricity generation, metal
smelting, burning of fossil fuels and vehicle exhaust also contribute a significant amount.
The effects of acidification include:Damage to the bark and leaves of trees. The trees lose their leaves, their growth will
be stunted and they will become more vulnerable to disease and insects.
Damage to ecosystems. Fish and their eggs in acid streams and lakes will die. This
problem is worst in early spring when acid snow melts and the fish are newly hatched.
Animals and birds that normally feed on the fish will be effected by the reduced food
Damage to buildings. Acid rain damages the surface of buildings and artwork especially
those made from sandstone, limestone or marble.
Damage to metals. Acid rain causes corrosion in metal structures such as railroad lines,
airplanes, cars, steel bridges, and underground pipes.