Levels of Radon Gas in Winnipeg Homes

Abstract

Residential radon levels were monitored on most homes occupied by approximately 1500 subjects in a case - control study of lung cancer conducted in Winnipeg, Canada. Indoor radon levels were measured by means of two 6 months integrated readings using CR39 alpha track detectors. The overall average level of radon based on measurements taken in the living areas and basements of 2916 homes was 148 Bq.m-3, more than 99% of the values were less than the Canadian indoor air guidelines of 800 Bq.m-3. Average radon levels in the living area (bedroom) were about one-third lower than in the basement. Significant differences were noted among measurements taken during different seasons of the year, with the average levels being highest during the autumn and winter months and lowest during the spring and summer months. Radon levels tended to be higher among homes in the Winnipeg metropolitan area located near the two rivers flowing through the city. The implications of these findings for epidemiological investigations of the relationship between environmental exposure to radon and lung cancer mortality are explored.