Social factors and behavioural reactions to radon test outcomes underlie differences in radiation exposure dose, independent of household radon level

Abstract

Radioactive radon gas inhalation causes lung cancer, and public health strategies have responded by promoting testing and exposure reduction by individuals. However, a better understanding of how radon exposure disparities are driven by psychological and social variables is required. Here, we explored how behavioural factors modified residential radon-related radiation doses incurred by 2390 people who performed a radon test. The average time from first awareness to receiving a radon test outcome was 6.8–25.5 months, depending on behaviour and attitudes. 20.5% displayed radon test urgency that reduced irradiation between awareness and outcome to 1.8 mSv from a typical 3.5 mSv, while 14.8% (more likely to be men) displayed delaying behaviours that increased exposure to 8.0 mSv. Of those with low radon, 45.9% indicated no future testing intention, underscoring the importance of original tests to reliably establish risk. Among people finding high radon, 38% mitigated quickly, 29% reported economic impediments, and 33% displayed delaying behaviours. Economic barriers and delaying behaviours resulted in 8.4 mSv/year or 10.3 mSv/year long term excess exposure, respectively, increasing lifetime risk of lung cancer by ~ 30–40%. Excess radiation doses incurred from behaviour were independent of household radon level, highlighting the strong influence of psychological and socioeconomic factors on radon exposure and lung cancer risks.

Consequences of changing Canadian activity patterns since the COVID-19 pandemic include increased residential radon gas exposure for younger people

“…It is important to note that long term inhalation of 100 Bq/m 3 radon in indoor air is the minimum exposure that incurs a statistically significant (16%) increase in lifetime risk of lung cancer and, as discussed earlier, www.nature.com/scientificreports/ equates to an estimated 4 mSv/y annual radon exposure 2,7,14,15,24,25 . Before the pandemic, 50.8% of Canadians experienced annual doses ≥ 4 mSv/y from residential radon gas 7,26 , and our work here shows that this proportion approached 60.4% during the COVID-19 pandemic. This emphasizes a shift in baseline radon gas exposures for a great number of people into the cancer-causing range, and especially so for younger adults.…”

“…Global, pre-pandemic average annual radiation doses from radon are an estimated 1.2 mSv/y, with some North American populations absorbing far higher annual doses [5][6][7][8]15,21,24,25 . Indeed, before the pandemic, average Canadian radiation exposures from radon were ~ 4 mSv/y 7,26 . Our work shows this rose by ~ 1 mSv/y after March of 2020, so that intra-pandemic averages reached ~ 5 mSv/y (Fig.…”

“…In addition to the built environment, behaviour and socioeconomics also influence radon exposure 9,[26][27][28][29][30] . For example, excess annual radiation doses (from radon) change substantially as a function of how fast individuals gain radon awareness and respond to personal exposure knowledge 26 .…”

“…In addition to the built environment, behaviour and socioeconomics also influence radon exposure 9,[26][27][28][29][30] . For example, excess annual radiation doses (from radon) change substantially as a function of how fast individuals gain radon awareness and respond to personal exposure knowledge 26 . Further, as older, more centrally located (relative to an urban core) North American properties have become more expensive within many real estate markets, they have also become less accessible to younger people who are instead more likely to live in newer, relatively more affordable properties with demonstrably higher average radon levels [6][7][8] .…”

“…This socioeconomic effect has also biased higher radon exposure towards people with the greatest number of young children living at home 7 , which is particularly concerning as still-growing and replicating human tissue is especially vulnerable to the negative effects of ionizing radiation exposure, including alpha particles from radon 21,[31][32][33][34][35][36] . Historically, this age-related skew has been somewhat offset by the fact that the behaviour of younger adults mean that they are also more likely to be in work, in school and/or more active outside, thus spending less overall time at home compared to older people 26 . We speculate, however, that this paradigm shifted as responses to the COVID-19 pandemic had collateral consequences on behaviour, including altered activity patterns that are unlikely to return to the pre-pandemic status quo.…”