Locations and reportsGeographic comparison
Compare radon data between locations
Compare EPA radon zones and reported testing statistics between U.S. states and counties, with every gap in the data shown as a gap.
Choose at least two locations
A comparison needs two places. Pick them above, or start from a state report and follow a county link.
What you can compare
EPA radon zone or zone coverage, the most recent reported year, buildings tested, the median reported result and the share of reported tests at or above 4 pCi/L.
What is charted
A bar chart is drawn only when every selected place holds that statistic. A chart with one real bar and two blanks invites the wrong conclusion, so it is not drawn.
What a gap means
An empty cell means the figure is not on file for that place. It never means zero, and nothing here is filled in from a neighbouring area.
Prefer to browse? All state reports · Query every figure in the data explorer
What the comparison shows
Pick up to three states or counties and see their radon figures side by side: the EPA radon zone, a prediction for the whole area, and the radon tests reported to CDC, which describe the tests reported there, not every home. A figure is set beside another only when every place you picked has it, and every gap in the data is shown as a gap.
EPA says homes with elevated levels have been found in all three zones and that every home should be tested. Only a test tells you the radon level in one home; each place's own report has its full figures and what to do next.