Short-term screening data from the United States Environmental Protection Agency State Residential Radon Survey (mid- to late 1980s) were combined with geologic data,
including estimated radium concentrations,
and location of screening measurements within the home,
along with a short- to long-term radon monitoring data conversion factor,
to predict annual average radon concentrations in homes in 3,079 United States counties.
We recently observed a significant positive association between mean county-level residential radon concentrations and lung cancer mortality in the CPS-II (17).