The Concept of Equivalent Radon Concentration for Practical Consideration of Indoor Exposure to Thoron

International Journal of Environmental Research and Public Health

Jing Chen¹ 

关键词: radon-220;    thoron;    radon-222;    radon;    indoor exposure;   

DOI  :  10.3390/ijerph9010286

来源: mdpi

【 摘 要 】

To consider the total exposure to indoor radon and thoron, a concept of equivalent radon concentration for thoron is introduced, defined as the radon concentration that delivers the same annual effective dose as that resulting from the thoron concentration. The total indoor exposure to radon and thoron is then the sum of the radon concentration and the equivalent radon concentration for thoron. The total exposure should be compared to the radon guideline value, and if it exceeds the guideline value, appropriate remedial action is required. With this concept, a separate guideline for indoor thoron exposure is not necessary. For homes already tested for radon with radon detectors, Health Canada’s recommendation of a 3-month radon test performed during the fall/winter heating season not only ensures a conservative estimate of the annual average radon concentration but also covers well any potentially missing contribution from thoron exposure. In addition, because the thoron concentration is much lower than the radon concentration in most homes in Canada, there is no real need to re-test homes for thoron.

【 授权许可】

CC BY   
© 2012 by the authors; licensee MDPI, Basel, Switzerland.