Air Pollution:

Uncertainty Exists in Radon Measurements

RCED-90-25: Published: Oct 16, 1989. Publicly Released: Nov 15, 1989.

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Pursuant to a congressional request, GAO provided information about the extent to which: (1) the Environmental Protection Agency's (EPA) program for assessing radon measurement proficiency provided assurance to homeowners that radon measurement results were accurate; (2) radon measurement devices and companies analyzing those devices accurately recorded radon levels; and (3) homeowners followed EPA-recommended testing procedures.

GAO found that: (1) EPA established its voluntary Radon Measurement Proficiency (RMP) Program to assess the proficiency of radon measurement devices and the companies analyzing those devices; (2) research and RMP data indicated a wide variance in accuracy among radon measurement devices and the companies analyzing them; (3) such factors as highly variable and fluctuating radon concentrations, use of relatively new measurement devices, and the extent to which companies applied quality controls could account for some of the differences in radon measurement accuracy; (4) a regional EPA survey found that 85 percent of homeowners who conducted radon tests did not follow an EPA recommendation to conduct a follow-up measurement; (5) radon mitigation firms indicated that many homeowners sought mitigation actions on the basis of results of a single short-term measurement; (6) RMP required companies to follow appropriate measurement protocols, demonstrate the ability to get measurement results to the proper homeowner, and demonstrate the ability to accurately measure radon within 25 percent of actual levels; (7) RMP did not include verification procedures to ensure that companies followed program requirements or require companies to implement quality control programs to ensure that they maintained a minimum performance level; (8) although 87 percent of devices tested under RMP during 1988 passed, firms marketed devices that did not meet RMP requirements; and (9) RMP participation increased from 40 companies in 1986 to over 700 in 1989.

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