What acid precipitation and two examples of the negative effects of air pollution.

Any form of precipitation, including rain, snow, hail, fog, or dew, that is high in acid pollutants, especially sulfuric and nitric acid. Acid precipitation has a pH of less than 5.6 (the normal acidity of unpolluted atmospheric water) and is often less than pH 5.0.

Air pollution can kill trees and can cause chronic disease