Earth Science

Human Impacts on the Earth Environment

Acid Rain

Study Tip
To remember the pollutants which cause acid rain:
SNAP: Sulfur Nitrogen Are Pollutants

Acid Rain

  • Buildings such as power plants or refineries expel sulfur and nitrogen oxides into the air, which combine with water vapor to produce sulfuric and nitric acids.
  • These acids in the atmosphere then are deposited onto the environment in the form of acid rain. It can also be deposited as fog, snow, or particulates (in dry areas).
  • Acid rain typically has a pH of less than 5.0, whereas regular rain has a pH of around 5.6.
  • The pH scale measures the acidity of a substance, the lower the pH value, the more acidic a substance is (more alkaline).
  • Acid rain is typically found in industrialized areas
Study Tip
To remember the pollutants which cause acid rain: SNAP: Sulfur Nitrogen Are Pollutants
Acid rain
Sulfuric acid, nitric acid, and mercury
are among the many types of pollutants that cause acid rain  

The Effects of Acid Rain

  • Acid rain destroys plants and makes them more vulnerable to destruction.
  • Some acids deposit on the ground dry, resulting in the soil being stripped of its basic nutrients.
  • Small animals often die when they are exposed to acid rain, causing larger animals to lose a valuable food source.
  • Fish die in water that is too acidic, and crops cannot grow in soil exposed to acid rain.
  • Ruins buildings.
  • Since acid rain can travel far, its effects can be spread to far distances.
Acid rain can  deteriorate trees
Acid rain can deteriorate trees and other plants as well.
Concept Check
  • Discuss how acid forms, beginning with the formation of acid from refineries or power plants
  • What is acid rain and why is it bad?