The 1990 amendments to the Clean Air Act addressed which issues?

• A. Global warming only
• B. Acid rain, ground-level ozone, stratospheric ozone depletion, and air toxics.
• C. Water pollution
• D. Noise pollution

Answer: (B)

The main idea being tested is what the 1990 amendments to the Clean Air Act expanded the law to address. These amendments broadened federal air-pollution control to tackle four major issues: acid rain, ground-level ozone, stratospheric ozone depletion, and emissions of air toxics. Acid rain results from sulfur dioxide and nitrogen oxides released by power plants and other sources, leading to damaged forests, lakes, and buildings; the amendments introduced tougher controls on these pollutants and even a cap-and-trade approach for sulfur dioxide. Ground-level ozone, the smog that affects health and visibility, led to stronger limits and controls on precursors like nitrogen oxides and volatile organic compounds to improve air quality. Stratospheric ozone depletion, caused by chlorinated chemicals such as CFCs, prompted measures to phase out ozone-depleting substances. Air toxics cover a wide range of hazardous pollutants from various industries, with stricter emissions standards to reduce health risks.

Water pollution and noise pollution fall under other laws and regulatory programs, and global warming was not the explicit focus of the 1990 amendments, even though climate concerns have grown in later years. So the four areas listed are what the 1990 amendments specifically targeted.