The sunny weather with highs in the 90s in Western Washington and near 100 in Eastern Washington is likely to combine with exhaust from motor vehicles, gas vapors, smoke and other air pollutants to produce higher concentrations of ozone, posing a ricks to people with lung and heart disease, children, older adults and people who are physically active.
When ozone levels are elevated, people should limit activities and the time they spend outside.
The federal limit of what’s considered safe is 0.075 parts per million averaged over eight hours. During the region’s heat wave Aug. 5, an Ecology air-quality-monitoring station near Enumclaw registered 0.082 ppm of ozone.
A single, isolated event does not mean the state violates the federal Clean Air Act standard for ozone. But that could change with repeated events, or if the Environmental Protection Agency tightens the standard after completing a scientific review of it in 2014.
If an area of the state becomes a repeat violator, it could force certain businesses to invest in new emission-control equipment or prompt the federal government to withhold federal funds for highway projects that could add to the pollution problem.
Some of the ways people can reduce smog levels include:
• Drive less and limit driving to the cooler times of day.
• Don’t use lawn mowers and other small engines.
• Don’t paint or use aerosol sprays until the weather cools.