"The levels we're seeing right now are ten to 20 times higher than the particle levels we would normally expect to see, and in some isolated cases, even higher than that", says Francis Ries, a Senior Project Engineer with Metro Vancouver.
They advise anyone with respiratory conditions like asthma, COPD, or heart disease or high blood pressure to limit their exposure to the smoke.
Dr. Sack says that ultimately, short-term exposure shouldn't worry most of us - our lungs typically expel the type of particles now smothering the Sound.
"You probably want to reduce the level of exercise you're doing outside", Dr. Sack said.
The Puget Sound Air Agency has issued a Stage 1 burn ban for King, Kitsap, Pierce and Snohomish Counties until further notice and is addition to existing fire safety burn bans.
"Elite athletes will face difficulties breathing, some early exhaustion, and in extreme cases if they're also dehydrated, they may experience confusion from difficulty breathing the air", Corneil said. "You see the number of forest fires increasing, and so there's going to be wildfires", Wineke said.
Take precautions: Everyone should take precautions when the air quality is unhealthy. "Places like shopping malls, community centres, swimming pools", she said.
During "very unhealthy" conditions, everyone is encouraged to stay indoors, avoid strenuous activity, close windows and doors, set air conditioners to recirculate, and use a HEPA air filter if possible.
In British Columbia, more than 10,000 homes across the province are on alert to evacuate due to the almost 600 wildfires burning, BC Wildfire Service spokesman Kevin Skrepnek said.
Air quality advisories were in effect for portions of Washington and OR, according to the weather service. Portland, Oregon, residents who were up early saw a blood-red sun shrouded in smoke and huffed their way through another day of polluted air.
The Federal Aviation Administration said airplanes bound for the Sea-Tac International Airport, Seattle's main airport, may be delayed because of low visibility.