National air quality has improved since the 1990’s, but many challenges remain in protecting public health and the environment from air quality problems.
Air pollution in the United States poses a public health threat affecting potentially millions of people throughout the country. It is associated with health problems that include increased emergency department visits and hospitals stays for breathing and heart problems, asthma, and increases in illnesses such as pneumonia and bronchitis.
Tracking air pollution can help people understand how often they are exposed to unhealthy levels of air pollution. Having these data can also help public health professionals or policymakers understand which areas may be most in need of prevention and control activities.
CDC and the Environmental Protection Agency have worked together to develop a way to make modeled estimates available for areas of the country that do not have air quality monitors and to fill in the time gaps when monitors may not be recording data. On the Tracking Network, both Air Quality System (AQS) monitor data and modeled datasets are available to track possible exposures to ozone and PM2.5.