RadonZoneCheck: The County Before the House

Field notes

The homepage separates EPA’s county-level predicted average from an actual indoor reading, repeatedly directing visitors toward home testing even in lower-risk Zone 3 counties. It organizes the directory by state and describes a search path by ZIP, then promises a county’s zone, national rank, and practical testing or mitigation context. The visible methodology is tied to EPA’s 1993 geologic and radioactivity assessment, while the listed zone counts total 3,144 counties.