Younger North Americans are exposed to more radon gas due to occupancy biases within the residential built environment

Abstract

Residential buildings can concentrate radioactive radon gas, exposing occupants to particle radiation that increases lung cancer risk. This has worsened over time in North America, with newer residences containing greater radon. Using data from 18,971 Canadian households, we calculated annual particle radiation dose rates due to long term residential radon exposure, and examined this as a function of occupant demographics. The current particle radiation dose rate to lungs from residential radon in Canada is 4.08 mSv/y from 108.2 Bq/m3, with 23.4% receiving 100–2655 mSv doses that are known to elevate human cancer risk. Notably, residences built in the twenty-first century are occupied by significantly younger people experiencing greater radiation dose rates from radon (mean age of 46 at 5.01 mSv/y), relative to older groups more likely to occupy twentieth century-built properties (mean age of 53 at 3.45–4.22 mSv/y). Newer, higher radon-containing properties are also more likely to have minors, pregnant women and an overall higher number of occupants living there full time. As younger age-of-exposure to radon equates to greater lifetime lung cancer risk, these data reveal a worst case scenario of exposure bias. This is of concern as, if it continues, it forecasts serious future increases in radon-induced lung cancer in younger people.

The efficacy of public health information for encouraging radon gas awareness and testing varies by audience age, sex and profession

“…From 2015–2020, Canadians purchased alpha track 90 + day radon detectors that they then deployed, returned for analysis, and later received their specific radon reading in a confidential manner. Radon outcomes for this cohort were reported recently in 20 . Non-profit study kits were $51.99.…”

“…Our total study group encompassed 18,971 Canadians who, following informed consent into a citizen science-based non-profit radon testing program, opted to perform long-term alpha track radon tests within their residential properties between 2015–2020. The full details of this cohort and their radon test outcomes were detailed recently 20 . Of the main cohort, 7,481 Western Canadian participants who were active within the study in 2018 were invited to retrospectively (in relation to completing a radon test) provide demographic and psychosocial survey responses to questions concerning their radon awareness experience and decision to test.…”

“…While predictable 35 , this finding becomes pivotal when one considers that younger people are more susceptible to negative health consequences from exposure. At least in North America, they are more likely to experience greater overall radon doses due to biases within the built environment 11 – 13 , 20 , 21 , 32 , 36 , 37 . As targeting younger people (especially those with children), is crucial for achieving the greatest reduction in population-based relative risk of lung cancer, one key recommendation from our work is for radon awareness strategies to increase investment in social media-based and/or word-of-mouth oriented communication techniques that better reach younger demographics (e.g., influencer campaigns).…”

“…Unfortunately, twentieth to twenty-first century construction practices have produced many buildings that capture, contain and concentrate radon to unsafe levels. In North America particularly, this continues to worsen as newer residential buildings are constructed increasing innate risks of producing high radon levels that are disproportionately impacting younger individuals with children 12 , 13 , 20 . Western Canada, for example, has been identified as a region of excessive residential radon gas exposure, with long term inhalation being responsible for approximately 1 new lung cancer case per day in some provinces 2 , 7 – 9 , 11 .…”

“…Secondly, to improve the “message-to-action efficacy” of public radon reduction programs, it is important that they be based on the best available evidence, as approaches over the past > 30 years have not achieved desired outcomes. In Canada, for example, despite decades of public investment in radon information and reduction programs, fewer than 6% of residential properties have been radon tested, and both radon levels in new properties and lung cancer incidence in never-smokers are at historic highs 12 , 13 , 20 , 21 . This is especially poignant when set against lung cancer prevention programs for tobacco exposure: a potent, preventable carcinogen similar to radon, but for which large-scale population exposure prevention through public health campaigns have been remarkably successful 31 , and has included investment in behavior-change research.…”