A preliminary design of a radon potential map for Canada: a multi-tier approach

Abstract

Canada is a vast country with most of the population living on a small portion of the land. However, for a national radon potential map, it is mandatory to cover the entire country including sparsely populated areas. Because of these characteristics, the radon map development for Canada is challenging. After briefly reviewing of radon map development in the world, this study considers a multi-tier approach to best use available however limited resources and to generate a national radon map in a timely fashion. In summary, radon potential maps for highly populated areas should be determined by direct indoor radon measurements where enough indoor radon data are available. In areas where indoor radon measurements are limited or not yet available, the radon potential maps could be developed from various data sources with a multi-factor scoring system including geological information on soil permeability, soil gas radon concentration and ground uranium concentration. In sparsely populated areas, radon potential maps can only be generated with geological predictive tools, especially in those areas where no houses have yet been built. Because indoor radon measurement data and geological information relevant to radon are very limited in Canada, a multi-step strategy is also worth considering in addition to the multi-tier approach.

Radon in Air and Water

“…A combination of indoor radon measurements and geological information are used to produced radon potential maps in Canada (Chen, 2009;Chen et al, 2011), Radon potential maps for highly populated areas are produced using indoor radon measurements where enough indoor radon data are available, whilst in areas where few or no indoor radon measurements are available, radon potential maps could be developed from various data sources with a multi-factor scoring system including geological information on soil permeability, soil gas radon concentra-tion and ground uranium concentration, although both these approaches are constrained by the sparsity of indoor radon measurements and geological information relevant to radon (Chen, 2009). …”

Achievements and current activities of the Canadian radon program

“…Canadian radon maps will be based on a variety of data, such as ground uranium concentration from airborne gamma ray spectrometric (AGRS) surveys, radon in soil, soil permeability, soil geochemistry, surficial geology, bedrock geology and indoor radon data (4) . To assist radon mapping, soil gas radon and ground natural radioactivity surveys have been conducted.…”

Radon soil gas in the Halifax Regional Municipality, Nova Scotia, Canada

“…Radon is a human health risk, as long-term exposure to high radon concentrations through inhalation is the second leading cause of lung cancer next to smoking (World Health Organization 2005). A radon potential map of Canada identified Nova Scotia and Winnipeg as the highest risk provinces (Chen 2009). …”

“…The measured soil gas radon concentrations varied significantly from 4 to 116 kBq m − 3. The SRP results ranged from 1 to 80 at the same sites; areas of high potential risk were identified (Chen 2009). Radon soil gas testing was done in southern Ontario previously (Je 1998).…”