Air Quality

Air quality is an important contributer to human health. Particulate Matter, Ozone, and Nitrogen Dioxide are three metrics that can be used to assess overall air quality. High concentrations of particulate matter in air can irritate the lungs and throat, causing coughing and sneezing. Breathing ozone can reduce lung function and cause chest pain and respiratory irritation. Exposure to nitrogen dioxide can lead to asthma.

Aerial view of a wildfire, by NASA Goddard Space Flight Center.

How is it measured?

Scores were calculated individually for Particulate Matter, Ozone, and Nitrogen Dioxide. Air Quality Index (AQI) values for each pollutant, calculated by the EPA, were assessed against thresholds (set by the EPA and shown in the table below) in order to obtain a report card score on a scale from 0–100%. Scores for each pollutant were then averaged for an overall air quality score for each region. Region scores were weighted by area to calculate an overall air quality score across regions.