Technical Booklet C Site Preparation and Resistance to Contaminants and Moisture·Page 16·3.7, 3.8
Radon affected areas definition
Areas with greater than 1% probability of radon levels exceeding the UK Action Level (200 Bq/m³) are designated as radon affected areas. Maps showing radon probability are available from the Northern Ireland Environment Agency.
Maps showing the probability of radon concentrations in dwellings in Northern Ireland are available in the Health Protection Agency report Radon in Dwellings in Northern Ireland: 2009 Review and Atlas. This document is available as a free download from the Northern Ireland Environment Agency's (NIEA) website http://www.ni-environment.gov.uk.
The areas on the maps with a greater than 1% probability of the radon level in a dwelling exceeding the current UK Action Level are designated radon affected areas. The Action Level is the maximum annual average radon concentration in dwellings that is set by the Health Protection Agency. Radon concentration is measured in becquerels per cubic metre (Bq/m³) and the Action Level is currently set at 200 Bq/m³.
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