Radon in Iowa Homes: Results of Screening Measurements

Homeowner-initiated short-term radon screening measurements in Iowa homes show that only about 30% of the homes have low enough radon levels - below 148 Bq/m (4.0 pC1/L) - that no follow-up measurements are necessary. Over 6 percent of the homes have screening measurements in excess of 740 Bq/m3 (20 pCi/L), a level at which prompt follow-up measurements are recommended. In all parts of the state, the range of radon results extends from low levels (below 37 Bq/m3 = 1 pCi/L) to high levels (above 740 Bq/m3). The average radon results tend to be higher than the state average in western Iowa and lower than the state average in eastern Iowa, with the highest average in northwest Iowa and the lowest in southeast Iowa; the reason for this geographical distribution is not known. These data indicate that a greater fraction of radon screening tests in Iowa exceed 148 Bq/m3 than in any other state for which the U.S. Environmental Protection Agency has carried out random radon screening surveys