Guided Notes on Human Impact on Air Resources Chapter 27, Section 3

1. Smog is a photochemical haze caused by the action of solar radiation on an atmosphere polluted by hydrocarbons and nitrogen oxides mostly from automobile exhaust.

2. The major chemical in smog is ozone (O 3 ), a gas molecule made up of three oxygen atoms.

3. Ground-level ozone is produced when combinations of air pollutants are exposed to sunlight.

4. The ozone layer in the stratosphere serves as a protective shield as it absorbs and filters out harmful ultraviolet radiation, which has been linked to eye damage and skin cancer.

5. Since the 1980’s, atmospheric studies have indicated a thinning of the ozone layer, especially over Antarctica. This depletion is entirely a result of human activity.

6. Acid precipitation is defined as precipitation with a pH less than 5.0. It forms when sulfur dioxide and nitrogen oxides combine with atmospheric moisture to create sulfuric acid and nitric acid.

Explain how coal-burning power plants can cause acid precipitation: These plants burn coal that contains the mineral pyrite (FeS 2 ). The sulfur is released as sulfur dioxide when coal is burned, and it combines with moisture in clouds to produce acid precipitation.

State the numerous harmful effects of acid precipitation: It damages aquatic ecosystems and vegetation It changes the pH of plants and soil It damages stone buildings and statues by accelerating the rate of weathering