Air Quality Standards

Air quality standards are the limits on the amount of certain pollutants allowed in outdoor air, set to protect public health and welfare. This topic covers how standards are set from scientific evidence, how areas are checked against them, and what follows when an area falls short. The Environmental Protection Agency sets national standards under the Clean Air Act, and states carry out plans to meet them.

People usually ask how air quality is measured and reported, what an air quality index means, and how pollution affects breathing and heart health. Questions also cover how to learn about the air in a given community and what happens when an area does not meet a standard.