Abstract: Indoor Radon
Concentration Data: Its Geographic and Geologic Distribution, an Example from the Capital District, NY
John J. Thomas, Helen M. Overeynder, Barbara R. Thomas
Most studies of the geographic distribution of indoor radon
levels are plotted by county or ZIP code. This method is used for the
radon
potential maps produced by the U.S. Environmental Protection Agency (EPA) and the New York State Department of Health (NYSDOH). The basis for tide mapping is the mean or median indoor
radon
count for all the data provided by NYSDOH within each geographic area.
While testing the indoor radon
analyses provided to the authors by CMT Independent Laboratories, we discovered data that deviated markedly from the EPA and NYSDOH means for the Capital District of New York (Albany and surrounding counties). Their screening indoor
radon
average concentrations. in pCi/L, indicate low potential for Schenectady (3.0), Saratoga (3.2), and Albany (3.7) counties; and moderate potential for Rensselaer (6.4) and Columbia (7.0) counties. Our database of over 3,000 analyses contains over 800 records of indoor
radon
counts above 4 pCi/L (14-47% of each county's analyses), many high enough to be rated as a serious health hazard.
In order to obtain greater precision of information, the authors plotted their indoor radon
data by street address using MapInfo, a Geographic Information System (GIS), and StreetInfo, MapInfo's TIGER address database. We compared the geographic distribution of our data to both the Bedrock Geology and Surficial Geology Maps of New York State. The results show a striking relationship of
radon
concentrations to bedrock, faults and permeability of surficial material. Data being compiled and mapped by street address by the NYSDOH in Erie County in western New York, confirm our results.
AAPG Search and Discovery Article #90954©1995 AAPG Eastern Section, Schenectady, New York