Do Edmonds or Lynnwood have the highest radon levels in the greater Puget Sound area?

Snohomish County, which includes Edmonds and Lynnwood, ranks as medium risk for radon gas exposure in the Puget Sound area. Counties closest to the Cascade and Olympic mountain ranges have the highest radon risk. Radon is a naturally occurring gas that seeps through foundation cracks and can cause lung cancer if inhaled, especially for smokers. Washington State offers a detailed radon map by ZIP code to check risk levels in your area.