Environmental health impacts of radon: Risk perceptions and mitigation efforts

Radon is a leading cause of lung cancer among nonsmokers in the U.S. and is responsible for approximately 21,000 deaths annually. The World Health Organization (WHO) recommends mitigation at levels of ≥ 2.7 pCi/L, a stricter threshold than Environmental Protection Agency’s (EPA) 4.0 pCi/L. This study examined risk perceptions and mitigation behaviors among residents with elevated radon levels in southwestern Pennsylvania, using qualitative and quantitative assessments of barriers and geospatial analysis to explore exposures and mitigation patterns. This research employs mixed-methods design, including a survey of households with elevated radon levels (n = 42), repeated radon monitoring in a subset of those households (n = 27), and focus groups/interviews (n = 17). The statistical analyses conducted were independent t-tests comparing risk drivers and perceptions in homes with mitigated vs. non-mitigated radon levels, as well as a Geographic Information System (GIS) analysis of radon data and socioeconomic/environmental indicators using the EPA’s EJScreen. Despite survey respondents having radon levels above EPA or WHO recommendations, only 38% took mitigation action prior to study participation, findings that may partly reflect inconsistent communication of guideline thresholds, as some participants were only informed of the EPA action level of 4 pCi/L and may not have recognized their levels as warranting action under the lower WHO guideline. An active mitigation system, including sub-slab depressurization (SSD) and mechanical venting, proved most effective in reducing radon levels. For those who chose not to mitigate, financial concerns and perceived lack of urgency were the primary barriers stated most often. Geospatial analysis found localized clusters of high radon levels in rural areas; some socioeconomic factors (poverty, disability prevalence) correlated with higher radon levels. Overall, this work highlights the significant impact that mitigation can have, while also underscoring the barriers that may prevent uptake in exposed populations.