Radon is a colorless and odorless gas that is commonly found in groundwater in Pennsylvania. The US Environmental Protection Agency considers radon to be a health concern because it can cause lung cancer.

Groundwater samples analyzed for radon have been collected by the Pennsylvania Water Science Center since the 1980s. As new samples are collected, results are automatically added to this interactive map web tool; please see the map for detailed information on the current number of samples collected. This application was developed in R and utilizes Shiny to organize, manage, and present data in an interactive web environment.
All data presented here is publicly available from the National Water Information System (NWIS) database. To explore where and when radon samples have been collected, use the sliders to select date and concentration ranges, specific counties and Principal aquifers. A data download tool is also provided that will output all currently-displayed data.
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