Table 1.
Summary of current government policy on radon in England*
| Mean indoor radon concentration in local area† | Current policy requirement‡ |
|---|---|
| New homes: | |
| <52 Bq/m3 (<3% of measurements >200 Bq/m3)§ | None |
| 52-86 Bq/m3 (3-9% of measurements >200 Bq/m3) | Basic preventive measures, such as a sealed membrane at ground level |
| At least 87 Bq/m3 (≥10% of measurements >200 Bq/m3) | “Full preventive measures” consisting of basic preventive measures plus installation of under-floor ventilation, such as fitting a radon sump and pipe¶ |
| Existing homes: | |
| <64 Bq/m3 (<5% of measurements >200 Bq/m3) | None |
| At least 64 Bq/m3 (≥5% of measurements >200 Bq/m3) | A series of targeted programmes offer free (government funded) measurements to homeowners on a rolling basis. If measured radon concentration is >200 Bq/m3, then homeowners are advised to remediate at their own expense |
*Policies in other parts of UK differ slightly. For details see document from Independent Advisory Group on Ionising Radiation.21
†Such as a 1 km or 5 km grid square, administrative area or division of postcode system.
‡In addition, areas with mean indoor radon concentration more than 36 Bq/m3 (>1% of measurements >200 Bq/m3) have been designated as “radon affected” areas. The Health Protection Agency recommends that anyone living in such areas should measure the radon concentration in their home and remediate if measured radon exceeds 200 Bq/m3. Employers are required to measure radon concentrations in both new and existing workplaces in areas designated as radon affected and in underground workplaces in any area, and to restrict exposure if measured radon exceeds 400 Bq/m3 (www.hse.gov.uk/radiation/ionising/radon.htm).
§The distribution of indoor radon measurements over different homes in an area is closely approximated by a log normal distribution, and so a predictable relation exists between mean indoor radon concentration in an area and percentage of measurements above any particular value. (See web extra appendix 1 for further details.)
¶There is no requirement to measure radon concentrations in these homes after they have been built or to activate the sump—for example, by installing a fan. Therefore, “full protective measures” currently required do not reduce radon concentrations more than basic preventive measures.