< 100 Bq/m³ — low
100 to 200 Bq/m³ — worth monitoring
> 200 Bq/m³ — elevated
Survey sectors
Solid outline: ≥ 20 tests — dashed: < 20 tests
Fills = sector aggregates (surveys). Discs = individual measurements. A fill is not a prediction for a house.
No measurement does not mean no risk.