Air Quality
Outdoor air quality has improved since the 1990s, but many challenges remain in protecting Americans from air quality problems. Ground-level ozone, the main part of smog, and particle pollution are just two of the many threats to air quality and public health in the United States.
![Air Aware a middle-aged man enjoying a breath of fresh air](https://webarchive.library.unt.edu/web/20201220233307im_/https://www.cdc.gov/air/images/AirQuality-AirAware-11x17-03-600px.jpg)
Air Aware
Learn more about protecting your health.
Page last reviewed: October 21, 2020
Content source: National Center for Environmental Health