Which legislation regulates air quality in the United States?

The Clean Air Act is the primary legislation that regulates air quality in the United States. Enacted in 1963 and significantly amended in the following years, this act establishes the framework for regulating the emissions of air pollutants from both stationary sources, like factories and power plants, and mobile sources, such as vehicles. It empowers the Environmental Protection Agency (EPA) to set and enforce air quality standards to protect public health and the environment from harmful pollutants, like particulate matter, sulfur dioxide, and nitrogen oxides.

The importance of this legislation lies in its comprehensive approach to controlling air pollution at the federal level, ensuring states comply with national air quality standards while also allowing them some flexibility to develop their own implementation plans tailored to local conditions. This regulatory framework has been instrumental in reducing air pollutants, thus significantly improving air quality over the decades.

Other options, while related to environmental protection, focus on different aspects. The Clean Water Act addresses water pollution and the management of the nation’s waterways, the Environmental Protection Act is more of an umbrella term often confused with the work of the EPA rather than a specific regulatory framework, and the Toxic Substances Control Act centers on the regulation of chemical substances and their impact on health and the environment but does not specifically address air quality.