Saturday, August 14, 2010
Radon gas, a radioactive product of uranium, can reach high levels in some houses, depending on the
local geology and house construction.
Radon potential maps
Scientists create radon potential maps by combining a variety of data, such as the locations of rocks containing high levels of uranium, locations of fractures, aeroradioactivity data, soil data on permeability and radon content, and indoor radon data. Not all of these types of data are available for every area, and radon potential maps for different areas may vary if they are based on different types of data.
For instance, radon potential maps and data sets prepared by the U.S. Geological Survey (USGS) of Montgomery and Prince Georges Counties, Maryland, and Fairfax County, Virginia, are based on different data.
The radon potential of Montgomery County was estimated by USGS geologists using measurements of soil radioactivity, measurements of soil-air radon, general geologic and soil maps, and indoor radon measurements reported by homeowners.
In Prince Georges County, indoor radon data were available, but the geologic maps were much less detailed than those of Montgomery County and good aeroradioactivity data were not available. Therefore, USGS geologists measured soil-air radon and surface radioactivity to create a radon data base for the
The radon potential of Fairfax County was estimated on the basis of an aeroradioactivity map and detailed soil maps that were available for the county and an indoor radon survey that the county conducted.
Three levels of radon potential were identified in the counties.
Low radon potential means that the majority of homes contain less than 4 pCi/L of indoor radon. Moderate radon potential indicates that one-third to one-half of the homes have more than 4 pCi/L. High Radon potential means that the majority of homes contain more than 4 pCi/L.
at 12:07 PM