Deutsch: Saurer Regen / Español: Lluvia Ácida / Português: Chuva Ácida / Français: Pluie Acide / Italiano: Pioggia Acida /
Acid rain is the result of sulfur dioxide (SO2) and nitrogen oxides (NOx) reacting in the atmosphere with water and returning to earth as rain, fog, or snow. Broadly used to include both wet and dry deposition. The acid rain page provides a great deal of information about this issue.
Other definition:
An Acid rain is Rainwater that has an acidity content greater than the postulated natural pH of about 5.6. It is formed when sulfur dioxides and nitrogen oxides, as gases or fine particles in the atmosphere, combine with water vapor and precipitate as sulfuric acid or nitric acid in rain, snow, or fog. The dry forms are acidic gases or particulates.
Other definition:
Acid rain is a term used to describe several ways that Acidic compounds fall out of the atmosphere, causing a variety of ground-level environmental effects. These effects include damage to forests and soils, fish and other living things, and human health. Acid Rain also reduces how clearly we can see through the air, an effect called visibility reduction.
See acid deposition, sulfur dioxide, nitrogen oxides.