Wildfire smoke impacted air quality across the United States from 2018 to 2023

Wildfire smoke seen by satellite. Credit: NASA

Wildfires are an increasing threat to air quality, affecting nearby areas and regions far downwind due to smoke dispersion. A new study published in Environmental Science & Technology examined how wildfire smoke affects the levels of two harmful pollutants, fine particulate matter (PM2.5) and ozone, across the United States from 2018 to 2023. Through an analysis of 600 air monitoring stations and satellite observations, researchers found that wildfire smoke significantly raised PM2.5 and ozone levels, leading to numerous days when air pollution exceeded health standards. Notably, wildfire smoke accounted for 25 percent of all days with unhealthy ozone levels, with 2023 seeing the greatest impact due to severe wildfires in Canada.

PM2.5 and ozone can cause respiratory and cardiovascular issues, with PM2.5 penetrating deep into the lungs and ozone irritating the respiratory system.