Radon gas has no odor or color, but it can't escape the nose of Patrick Otterson, a certified radon tester and mitigation expert with more than 25 years of experience. He tests homes' air for presence of the gas—which can damage lung tissue and lead to lung cancer—and devises solutions to reduce or remove it. To do so, he fits buildings with active soil depressurization systems designed to keep radon at bay while maintaining the aesthetic appearance of the structure.