What is the main purpose of the Clean Air Act (CAA)?

The main purpose of the Clean Air Act (CAA) is to protect human and environmental health from air pollution. Enacted in 1963 and significantly amended over the years, this piece of legislation focuses on ensuring that air quality is safe for all living organisms and mitigates the harmful effects of air pollution on both humans and the environment. The act achieves this by establishing national standards for air quality and setting limits on the emissions of hazardous air pollutants, which helps to prevent respiratory diseases, environmental degradation, and climate change challenges.

The other options, while related to environmental and public health, do not accurately capture the primary focus of the CAA. For instance, regulating international air traffic pertains to aviation law rather than air quality. Monitoring weather patterns falls under the domain of meteorology, which the CAA does not directly address. Managing hazardous waste materials is governed by a different set of regulations, primarily outlined in the Resource Conservation and Recovery Act (RCRA). Thus, the emphasis on air quality and health protection solidifies option B as the correct and most relevant answer.