Why’s it so hazy? Here’s what we know about factors affecting Pierce County air quality
Pierce County air quality has worsened in the past two days. The Puget Sound Clean Air Agency forecasts moderate to unhealthy air pollution.
The agency’s real-time air pollution map shows Tacoma and Pierce County inside an area with unhealthy to moderate air levels.
If an area reaches unhealthy levels, “everyone should reduce our exposure if possible to the outdoors,” said Jacob DeFlitch, a meteorologist at the National Weather Service.
Moderate levels are acceptable for most, though can be a be risk for some, particularly people who are sensitive to air pollution. Unhealthy levels bring possible health effects to all people.
Decreasing air quality levels can happen for a variety of reasons.
“We had a number of factors adding up, unfortunately, all at the worst time,” said Phil Swartzendruber, the air resources specialist at Puget Sound Clean Air Agency.
Air quality decreases in Pierce County began on July 4 with wildfire smoke from British Columbia wafting into the Pierce County area.
From that smoke alone, the Puget Sound air quality index leaped up to moderate air quality.
Tuesday night, with Fourth of July fireworks celebrations, the air quality declined further into unhealthy levels. Fireworks smoke can be trapped in the ground-level air with clear skies and cooler weather, according to Swartzendruber.
“There are probably a number of neighborhoods that have a lot of fireworks smoke on top of that wildfire smoke,” Swartzendruber said.
The McEwan Fire near Shelton, Thurston County, might also contribute to lower air quality levels in Pierce County.
The McEwan fire began around 2 p.m. Tuesday. The brush fire in Mason County, which has led to home over 200 home evacuations, has spread to over 250 acres, according to the Washington State Department of Natural Resources.
Swartzendruber is hopeful air-quality levels will be back to moderate by Wednesday afternoon, but the McEwan Fire is the wild card.
“It’s really tough to predict what that fire is going to do,” Swartzendruber said. “If the McEwen fire flares up… Pierce County could actually see a lot more wildfires smoke from that fire.”
A chart and more information about air quality levels determined by the Air Quality Index (AQI), can be found at https://www.pscleanair.gov/165/About-the-Air-Quality-Index.
