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Radon Maps of New York State by County and Town


These radon maps and tables,
created using spatially located
results collected over two decades
and correlations to geology, were
prepared and posted in early 2007.

Living Area Long-Term Estimates
NY State Map : living area radon levels

Basement Short-Term Estimates
NY State Map : basement radon levels

In 2007, the New York State Department of Health prepared maps for each county in New York State showing the estimated percent of homes with greater than 4 pCi/L indoor radon for the towns and cities in the county. The maps have been prepared using a statewide database of over 45,000 basement screening measurements and over 11,000 long-term living area measurements. These measurements have been made through an ongoing detector distribution program initiated by the Health Department in 1986. For areas in the State where few measurements have been made, the percent of homes with above 4 pCi/L has been estimated using indoor radon correlations with the surficial geology of the area. The estimates of the percentage of homes with greater than 4 pCi/L and the uncertainties in these estimates were obtained using a radon mapping program developed at the Lawrence Berkeley National Laboratory.

The Environmental Protection Agency (EPA) recommends that actions be taken to reduce indoor radon concentrations if the primary living areas of a home have radon concentrations above 4 pCi/L. There are two maps for each county. One map is based on short-term basement measurements and the other is for long-term living area measurements. The long-term living area maps indicating the percent of homes greater than 4 pCi/L are based on long-term tests made over the course of a year with the detectors placed in a primary living area of the home. Approximately 90% of the detectors were placed in living rooms, family rooms, and bedrooms. The long-term living area estimates are the best indicators for the percent of homes in an area that are above the EPA action guideline concentration of 4 pCi/L. The basement short-term estimates are based on short term tests (usually 2 to 7 days long) taken in the basement of a home under closed house conditions. Basement radon concentrations average between 2 to 3 times higher than first-floor concentrations and the percent of homes with basement screening concentrations above 4 pCi/L are considerably greater than the long-term living area estimates. If a primary living area such as a family room or bedroom is located in the basement, the probability is greater that these rooms will be above 4 pCi/L than rooms located on the first or second floor. A table has also been prepared for each county containing some additional information. The number of basement screening measurements used to estimate the percent homes greater than 4 pCi/L is listed for each town and city. Also listed is the one standard deviation uncertainty in the estimates for the percent of homes with greater than 4 pCi/L. For towns with few or in some cases no measurements, the uncertainty is quite large. Projects are underway to obtain additional measurements for areas with few measurements.

In addition to the county maps, maps of New York State showing the percent of homes with greater than 4 pCi/L (long-term living area and basement short-term) for the counties have also been prepared. Statewide, the long-term living area estimate for homes above 4 pCi/L is 5 percent and the basement screening estimate is 18 percent above 4 pCi/L.

The intent is for the maps to be used as a guide in matters regarding measuring homes for indoor radon and for the implementation of radon-resistant building techniques. Even in areas with below average levels of indoor radon, it is prudent to measure homes for indoor radon. In areas with above average concentrations of indoor radon, existing homes should be measured and new construction should employ radon-resistant building techniques. For additional information, please call the Radon Hotline at 1-800-458-1158 extension 27556.

Radon Basement Featured Image
Township level estimates of the percent of homes with indoor radon exceeding the U.S. Environmental Protection Agency's (EPA) recommended action level of four picocuries per liter of air (pCi/L).

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