Puget Sound Clean Air Agency

Photo: Agency Webcam shot of brown layer of smog obscuring Mt. RainierWhat is Smog?

Smog builds when summertime sunlight "cooks" everyday emissions from motor vehicles, industry, paints, solvents and gasoline fumes. When the pollutants react with the summertime sunlight, they form ground-level ozone, the main component in smog.

The Puget Sound area typically experiences smog problems during warmer summer months, when temperature reach 85 degrees or higher, and especially when winds are stagnant or light.

Smog-forming pollutants are primarily generated by traffic and activities in urban areas. Wind patterns, however, blow this pollution into outlying suburban and rural areas.

What are the impacts of smog?

  • Smog affects our health. When ozone is closer to the earth's surface in a layer called the troposphere, it can harm our health. Exposure to ozone can cause asthma attacks, lung inflammation and other respiratory illnesses. High levels of ozone pollution cause discomfort for people with asthma or other lung ailments. Ozone may damage lung tissue even in healthy people. It makes our eyes itch, burn and water. Even healthy people can be affected if they exercise outdoors.

  • Smog mars our mountain views. On hot, stagnant days, we often have a brown, hazy ring around Mt. Rainier and other area mountains. The U.S. Forest Service reports that smog-related pollution damages trees, moss and lichen in Pacific Northwest forests.

  • Smog can also affect economic growth in the Puget Sound region. If we exceed the federal health standard for ozone, a pollutant in smog, more than three times in three years, we will not be able to maintain our status as a "'clean air region" and be stigmatized for having dirty air. If this were to happen, we would have expensive new regulatory requirements, new businesses may not want to come to the region, and existing businesses would face tougher requirements for expansion.

Don’t get bogged by smog: Here’s what you can do

By adopting some of these permanent behaviors, we can all do our part to reduce smog, and protect our health and our environment:

  • Drive less – and bus, bike, walk, or carpool more. Cars and trucks typically produce more than 700,000 pounds of smog-forming pollutants on a summer day in Puget Sound region.

  • Quit idling around. Idling for longer than 30 seconds actually burns more fuel than turning off and restarting your engine. Turn off your engine instead. You’ll save money too!

  • Be air aware. Join our Clean Air Action Network, and be among the first to know when air-quality conditions indicate the need for early action.