Smog pollution in Pierce County, including communities and areas near the Cascade foothills, could reach unhealthy levels this week as temperatures rise throughout the region, according to the Puget Sound Clean Air Agency.
Health officials warn that exposure to smog can trigger asthma attacks, make breathing difficult, exacerbate lung and heart problems and weaken the immune system. The state Department of Health recommends that people in Pierce and King counties who are sensitive to air pollution limit their time spent outdoors during what amounts to a smog alert this week.
Air pollution is especially harmful to children, people with heart and lung problems, and adults over age 65, officials said.
Smog builds when summertime sunlight “cooks” everyday emissions from motor vehicles, industry, paints, solvents and gasoline fumes, said a spokeswoman for the Clean Air Agency. The result is ground-level ozone, the main component in smog.
Based on weather forecasts, the agency said smoggy conditions will mostly impact communities in the Cascade Mountain range foothills of King and Pierce counties. Pollution generated by vehicles and activity in the urban population centers such as Tacoma and Seattle accumulates as it moves to outlying suburban and rural areas.
Temperatures in or near the low 90s are predicted for Wednesday and Thursday by some forecasters.
The smog warning comes at the same time that a burn ban is being planned for Pierce County in response to hot, dry weather. The ban is scheduled to begin at 8 a.m. Thursday on all outdoor burning, except campfires, barbecues and self-contained gas or propane stoves.