Air Quality

A foundation of human health and wellbeing is breathing fresh air. The Air Quality Vital Sign tells us about people's exposure to impaired air quality in Puget Sound. Air quality varies by location and across the urban-rural gradient due to weather patterns, topography, and pollution sources. Sources of air pollution in Puget Sound include vehicle emissions, industrial emissions, wildfire smoke, and residential burning of wood and debris.

Wildfire smoke in Seattle. Photo credit: Bruce Englehardt.

Key Vital Sign Messages

  • Clean air is vital for everyone. The Washington Department of Ecology works in partnership with local clean air agencies and tribes to monitor and track emissions to make sure outdoor air quality meets federal and state standards. Three local clean air agencies manage air quality in Puget Sound.
  • Air pollution impacts both urban and rural communities throughout the Puget Sound area from a broad range of sources, including wildfires, residential wood combustion, traffic and industrial sources.
  • The severity of local and regional wildfires has been the main cause of Puget Sound residents’ exposure to PM2.5 concentrations in recent years. In 2020, all Puget Sound residents were exposed to impaired air quality, with many areas reaching the very unhealthy and hazardous ranges of PM2.5 for several days.
  • Over the past several decades, the planet has increasingly warmed due to climate change, causing more potential for wildfires. With hotter and drier conditions in the years ahead, we expect more wildfires and longer fire seasons. Puget Sound’s air quality and public health will be more at risk.
  • Air toxics are hazardous air pollutants known or suspected to cause a broad range of serious health effects, including cancer. In the Puget Sound area, diesel particulate matter (DPM) accounts for most of the potential cancer risk from all air toxics. This means that communities near major roadways, like the Chinatown-International District in Seattle located along I-5 and I-90, are exposed to higher concentrations of toxics associated with vehicles.

Background Documents

Other Resources

Contributing Partners