Wildfire Smoke Alert for September 17, 2020


The Puget Sound Clean Air Agency has released a Wildfire Smoke Alert for the Puget Sound Region. During smoke events, the main pollutants of concern are the fine particles suspended in the air that can affect the respiratory and cardiovascular systems and increase health risks, especially for sensitive groups.

The Environmental Protection Agency’s Air Quality Index (AQI) in the Seattle and Tacoma areas is currently in the “Unhealthy” category, meaning some members of the general public may experience health effects; members of sensitive groups may experience more serious health effects.

air quality alert
Air Quality Alert from www.airnow.gov

  • Sensitive groups: Avoid prolonged or heavy exertion. Consider moving activities indoors or rescheduling.
  • Everyone else: Reduce prolonged or heavy exertion. Take more breaks during outdoor activities. 

When the AQI is greater than 100, it is recommended that everyone stay indoors and keep windows closed, especially sensitive groups, such as older adults and young children, pregnant women, and those with a breathing or heart condition. When the AQI exceeds 150, you should to take steps to limit your exposure, including limiting time outdoors to one hour. Read more information on the health effects of wildfire smoke and tips for protecting yourself on the Centers for Disease Control and Prevention (CDC) Wildfire Smoke webpage.

The Environmental Protection Agency AirNow website provides a reliable report of the current and forecasted air quality in your area. AirNow provides the daily AQI, a rating of how clean or polluted the outdoor air is, along with any potential health effects and recommended steps to reduce exposure.  

To check the current AQI, visit the AirNow website.

Wildfire smoke and COVID-19

During the COVID-19 pandemic where reduced occupancy is required for working inside, it is best to stay home and indoors where the air is filtered and keep windows and doors closed. If possible, use a portable air cleaner with HEPA filtration to reduce particulate exposure in a specific room or space.  Consult with the Environmental Protection Agency (EPA) Air Cleaners and Air Filters in the Home guidance document.

To limit indoor particles, it is best to keep windows and doors closed as much as possible and rely on the University’s heating, ventilation, and air conditioning (HVAC) systems’ filters, which typically remove about 90% of harmful pollutants in wildfire smoke. While HVAC filters remove harmful particles, they do not remove residual odors from wildfire smoke, which can contain particles and gases in concentrations that are not known to be hazardous to health. However, if there are very strong smoke odors in a building, contact EH&S for assistance.

In naturally ventilated buildings (buildings without mechanical ventilation systems), the indoor temperatures may rise due to windows being closed. If it becomes unbearably hot, portable fans and air-conditioning units can be used to cool the space. To reduce the potential for spreading the virus that causes COVID-19, the discharge airflow should be directed away from the body and face of other people. Prior to the use of portable air conditioning units, check with your department leadership and the building coordinator to ensure that the facility electrical system can meet the energy demand.

Read about the impacts of wildires in the Pacific Northwest from UW experts, including the ways the pandemic is increasing our community’s vulnerability to extreme wildfire events in the region.

Indoor air quality at the UW

Visit the Indoor Air Quality page on the EH&S website for more information and instructions for requesting an indoor air quality evaluation.

More information

Visit the Washington State Department of Health COVID-19 and Wildfire Smoke webpage to read frequently asked questions for wildfire smoke and COVID-19 during the 2020 wildfire season.