This story originally appeared on Filterbuy.
While the recent wildfires in Western states have introduced new concerns about air quality, the U.S. has made huge strides in the reduction of air pollution in recent decades.
As a result of the Clean Air Act and modern pollution control technologies, emissions of common air pollutants have dropped by more than 70% since 1970, according to new data from the Environmental Protection Agency.
These reductions, which the EPA claims have significantly improved the environment and human health, occurred despite a growing population, increased energy use and more cars on American roads.
The EPA measures air quality through the Air Quality Index, or AQI. The AQI rates air quality with values between 0 and 500. An AQI over 100 is considered unhealthy for sensitive groups, and anything over 150 is unhealthy for everyone. Major pollutants accounted for by the AQI and regulated by the