One day, Watras tried something different. He walked into work and immediately
headed back toward the exit. The radiation detector blared.
“It was like a lightbulb in my head went off,” Watras recounted during a recent
interview.
Watras realized the source wasn’t his workplace. It was his own home. Power
plant of cials brought in a radiation detector and found astronomic levels.
Originally identi ed by a German physicist in 1900, radon is everywhere in the
air. It gets released from the ground as uranium decays in rocks and soil. It’s
quickly converted to polonium, another radioactive element, which can attach to
dust particles before being deposited in lungs.
Until Watras’ case, concern about human exposure had been largely limited to
miners. No one knew the odorless gas could build to such dangerous
concentrations in a home.
Federal environmental regulators moved remarkably fast.
EPA of cials started encouraging homeowners to test for radon
in 1986, eventually estimating some 6 million homes had
enough radon to warrant repairs. Basements and rst oors
were the main problem.
While the EPA says there’s no safe level of radon exposure, the
critical threshold was set at 4 picocuries of radioactivity per
liter of air. At that concentration, the agency says, people
should install fan systems that pipe radiation away from the
home.
Although some scientists at the time argued the government
was using scare tactics without evidence, the EPA’s advice to
The EPA created its rst radon guide for the
public in 1986.
homeowners had staying power.
“We don’t get much pushback anymore,” said Bill Field, a University of Iowa
radon expert who served on the EPA’s Science Advisory Board. “It’s generally
accepted by the scienti c community.”
In 2005, the U.S. Surgeon General warned that prolonged exposure “can present a
signi cant health risk to families all over the country.” In 2011, the EPA called
radon testing “an easy and inexpensive way to save a life — many lives.”
But from the moment the federal warnings started, some lawmakers worried the
government would apply a double standard to the housing it most directly
controlled.