In Northern Europe and North America millions of trees have died due to acid rain. The
acid reaches into the roots and leaves of the trees and kills them. Some lakes are so acidic that all the fish and other marine
life have died. Tiny water plants have also been killed off. If trees are not killed by acid rain they are affected and lose
a lot of their leaves.
Acid rain is defined as rain that is more acidic than rain water. Normal rain water is
usually slightly acidic because the carbon dioxide in the air mixes with the water to form carbonic acid. However gases from
factories and motor vehicles make rain much more acidic than usual. These gases combine with water in the air to form
acids such as sulfur dioxide and sulfur trioxide. These acids then attack the environment.
Plants and animals are not the only things that are effected by acid rain. Buildings can
also be effected. The acids speed the rusting of metal buildings and stone buildings. Metal pipes also rust must quicker in
areas where there is acid rain.
Most acid rain has a pH of 4.5-5.5. However in the USA acid rain as acidic as vinegar
(pH 3) and lemon juice (pH 4) has been recorded.