Portland and Vancouver have a radon issue– one that has been here for thousands of years–and it is not going to go away. The soil in the Willamette Valley, much of Clark County, and the Columbia River Gorge has a granite component, Ice Age material brought down the Columbia River from Montana repeatedly between 10,000 and 12,000 years ago, during the Missoula Floods. It is found as sand, gravel, cobblestones, even boulders. This granite, mixed into the upper layers of our soil, contains uranium, which breaks down naturally over time and produces radon gas. Invisible and with no smell, radon is drawn upward into our homes (regardless of architectural style,…
