A Case for Targeted Radon Control Policies in Olmsted County
In the United States, lung cancer is the leading cause of cancer death1–3. Radon is the leading cause of lung cancer in nonsmokers and the second leading cause of lung cancer overall1,2,4. The Environmental Protection Agency (EPA) estimates that 21,000 deaths occur nationwide each year as a result of radon exposure1,2. In Minnesota, this is a serious public health concern since the average radon levels are more than three times higher than the rest of the nation and more than two in five homes have levels that put the residents at risk5. The EPA groups counties with exposure to radon into three different zones (i.e. zone 1, zone 2, and zone 3) with zone 1 having the highest potential to have an indoor radon screening level greater than 4 pCi/L — the EPA’s action level for radon6. As residents of Olmsted County, we are in zone 15. It is estimated that about half the homes in our county have radon levels that exceed 4 pCi/L7, and according to the 2015 Olmsted County CHNA Survey, only 12% of residents met all six principles for Healthy Homes primarily due to residents not knowing whether their homes had ever been tested for radon8.
Radon is a colorless, odorless gas that is found naturally in the environment through the decay of uranium. The process of uranium decay in the soil will release radon into the air or dissolve into groundwater. As the radon rises through the soil, it can enter buildings through various cracks, pipes, openings, and accumulate inside the building1. Humans are exposed to radon through the inhalation route1,9. Although oral and dermal routes are possible, the UK Health Protection Agency in 2009 concluded that there is insufficient evidence to suggest that radon exposure through other routes, aside from inhalation, is associated with lung cancer9. Inhaled radon damage lung cells causing DNA damage and potential development of lung pathology2. Studies that have evaluated radon exposure and its health effects primarily consists of 1) cohort mortality studies of underground miners that were exposed to radon and its association to lung cancer, 2) residential case-control studies that looked at individual exposures and cases of lung cancer, and 3) ecological studies that evaluated certain diseases in a geographical location and average radon levels in that area. Despite the EPA’s action level of 4 pCi/L, any level of radon poses some health risk5. Moreover, due to the cold weather, the frequency and duration of exposure to radon is also higher in Minnesota as it is more common to be indoors where the buildings are closed up and heated for most of the year5. Thus, it is important to minimize exposure as much as possible.
Biomarkers of exposure to radon and its progeny are the substances themselves9. Exposure to radon can be detected in the bone, teeth, blood, and hair9. More importantly, due to its short half-life of 3.82 hours, timing of the sample is important. While there have been many models and studies that have estimated exposure, the uncertainty and assumptions for these biomarkers of radon are not considered useful9. In regards to susceptible populations, children may seem to be more susceptible to radon exposure since they breathe more air per kilogram of body weight relative to adults. However, this is negated by the fact that they have less developed alveoli. Further, information from children who worked in the mines in China did not support increased susceptibility due to exposure of radon9. Conversely, smokers who are exposed to radon have a much higher risk of developing lung cancer when compared to nonsmokers. It is estimated that the lifetime risk of radon-induced lung cancer death for never-smokers is 7 per 1000 as compared to 62 per 1000 for ever-smokers2. The primary organ that is impacted by radon exposure, in both humans and animals, is the lung. A potential early indicator of lung cancer is the frequency of abnormalities in sputum cytology, since, there is positive correlation between cumulative radon exposure and the frequency of abnormalities. However, exposure to other carcinogens (e.g. cigarette smoke) can also elicit abnormal sputum cytology. Thus, measurement of this biomarker may not be a reliable tool in ascertaining health effects due to radon9. Nevertheless, lung cancer is the primary toxicologic concern with radon exposure1,9.
Despite the wealth of information that is known about radon exposure and the higher level of risk in Olmsted County, you would think that policies exist to enforce the EPA’s action level of 4 pCi/L. There is not. Although information specific to Olmsted County or Minnesota wasn’t found, there are multiple studies that suggest that the primary barrier in enforcing radon mitigation in homes with a level greater than 4 pCi/L is cost2,3. Mitigation of radon is estimated to cost $1200 on average and efforts for universal radon testing versus targeted efforts were cost-prohibitive2. Using estimates in 1993 dollars, universal testing efforts were estimated at $480,000 per life year saved as compared to targeted testing at $140,000 per life year2. Moreover, shifting testing to high-risk groups, such as heavy smokers, substantially lowered the cost to a more cost-effective amount of $30,000 per life year saved. This is an important point because funding for radon is unlikely to increase. In fact, funding for radon control programs in the United States have declined by two thirds since 1997 and the number of homes since that exceed the EPA’s action level remains just as high2. Given the increased risk of lung cancer in smokers who are exposed to radon coupled with limited resources, a case should be made for a policy that enforces the testing and mitigation of radon in the homes of smokers. Considering the primary barrier of cost, funds recovered from this targeted approach could be used towards assisting smokers that have financial need. As residents of Olmsted County, we should lobby our local government for such legislation to ensure maximum utility of our tax dollars.
References
1. Bain AA, Abbott AL, Miller LL. Successes and Challenges in Implementation of Radon Control Activities in Iowa, 2010–2015. Prev Chronic Dis. 2016;13:1–7. doi:10.5888/pcd13.150596
2. Lantz PM, Mendez D, Philbert MA. Radon, smoking, and lung cancer: The need to refocus radon control policy. Am J Public Health. 2013;103(3):443–447. doi:10.2105/AJPH.2012.300926
3. Gray A, Read S, McGale P, Darby S. Lung cancer deaths from indoor radon and the cost effectiveness and potential of policies to reduce them. BMJ. 2009;338(7688):215–218. doi:10.1136/bmj.a3110
4. Chen J, Vowell D, Yard B, et al. Radon in Schools: A Brief Review of State Laws and Regulations in the United States. Int J Environ Res Public Health. 2018;15(10):2149. doi:10.3390/ijerph15102149
5. Health MD of. Radon in Homes. https://www.health.state.mn.us/communities/environment/air/radon/index.html. Published 2004. Accessed March 8, 2019.
6. Agency USEP. EPA Map of Radon. https://www.epa.gov/sites/production/files/2015-07/documents/zonemapcolor.pdf. Published 2017. Accessed March 8, 2019.
7. Olmsted C of. Radon Testing. https://www.co.olmsted.mn.us/OCPHS/programs/food/Pages/RadonTesting.aspx. Published 2019. Accessed March 8, 2019.
8. Olmsted C of. Health Factors Physical Environment. doi:10.1016/b978–1–4832–0111–5.50013–6
9. Keith S, Doyle JR, Harper C, et al. Toxicological Profile for Radon.; 2012. doi:10.1201/9781420061888_ch137
