Wood Smoke Pollution

With cooler months ahead, our Agency is focusing on reducing pollution caused by wood burning for home heat. Smoke from wood burning is a major contributor to increased air pollution in the Puget Sound region and directly impacts neighborhoods and communities since smoke is often trapped close to the ground by cold temperatures. It is also the main reason air quality burn bans are issued.

Our concern about wood smoke is compounded by our concern about the impact of the COVID-19 respiratory pandemic on our residents. Preliminary studies have shown that increased air pollution puts people at a greater risk of being impacted by COVID-19. These impacts are increased by short- and long-term exposure to particulate air pollution, including pollution caused by wood smoke. One study conducted in the US found that small increases in particle pollution exposure are linked to large increases in the COVID-19 death rate.1 COVID-19 also disproportionately impacts people with underlying health conditions, those over the age of 65, and people of color, specifically Indigenous, Black and Latinx communities.2 Many of these same communities are disproportionately impacted by air pollution.

Due to the pandemic, we expect more people to spend more time at home to reduce the spread of the disease, telework, and take care of family. Historically, more time spent at home leads to increased particulate pollution since many people use wood stoves to stay warm. We saw evidence of this earlier this year when the state’s stay-at-home order overlapped with some colder days (see the graphs below). Particulate matter, known as PM2.5, are pollution particles smaller than 2.5 microns. These microscopic pieces of pollution can cause breathing and heart problems. The health effects even from short-term exposure are serious, and include asthma, other respiratory issues, heart attacks, and premature death. 

The charts below show time-of-day average values of PM2.5 during weekdays in March-April at four Puget Sound area monitoring sites. They compare the average PM2.5 levels for the period from 2020 (in red) with the average values from 2017-2019 (in blue).

Tacoma Graph

Duwamish Graph

Marysville Graph

Located in residential neighborhoods, our air monitors in South Tacoma and Marysville observed the biggest difference in harmful particulate matter concentrations in March-April of this year. Our experts believe that increased pollution is driven by burning wood for home heat.

With the COVID-19 pandemic continuing and more people staying indoors as colder weather nears, now more than ever we need to work together to reduce our contribution to our neighborhood air pollution levels. And there is good news – everyone can help in this effort. Below are tips that you can take to do your part to help keep the air clean and healthy for everyone to breathe.  

Help prevent air quality burn bans and keep your community healthy!  

  • If you need to burn, burn cleaner using our clean burning guidance.
  • Limit recreational (small outdoor) fires.
  • Share this information with your community through social media and neighborhood groups (contact kellyo@pscleanair.gov for additional resources).
  • Sign up for our air quality burn-ban list so you are in the know
  • Recycle your old wood stove, or upgrade it to cleaner heat through our wood stove program.

    • $350 reward available to eligible homeowners in King, Kitsap, Pierce, and Snohomish Counties.
    • $1,500 discount towards new heating for eligible Snohomish County homeowners.

By Kelly O'Callahan, Air Resource Associate, Puget Sound Clean Air Agency