radon test at home

Radon is a colorless, odorless naturally occurring radioactive soil gas produced from the process of radioactive decay of radium, thorium, and uranium in soils and rocks throughout the world. Rather than radon itself, the radioactive products of its degradation are actually the issue. These emitters, or radon daughters, include alpha particles that may stick to dust and/or the delicate lung epithelium as it is inhaled, resulting in DNA damage and potentially leading to lung cancer. The US Environmental Protection Agency estimates that radon exposure is the leading cause of lung cancer in nonsmokers and the second most common cause in smokers, with a lifetime risk of lung cancers increasing in a linear fashion with increasing radon exposure. For homes in which a significant level is detected using approved detection kits, engaging a certified contractor to assess radon levels (repeating tests if warranted), sealing fractures in the foundation, and providing appropriate risk mitigation strategies such as increasing ventilation in the lower level of the home is suggested (choice C is correct).

Geographic prevalence maps of radon prevalence created by the Environmental Protection Agency show greater concentrations of expected radon levels in the upper Midwest and eastern portions of the United States, with the southern portions of the United States demonstrating lower prevalence (choice A is incorrect). Although no levels of radon have been deemed safe, the agency has extrapolated that levels measured at 4 pCi/L or greater are actionable. However, radon levels even lower than this threshold are also associated with slightly increased incidence of lung cancer, even in never-smokers (choice B is incorrect). The actual risk for developing lung cancer depends on radon concentration, the duration of exposure, and smoking habits, with smokers having a much greater risk for lung cancer development. More recently, studies have also associated the absence of the GSTM1 and GSTT1 genes with increased risk of lung cancer development in those with significant radon exposure.

Radon migrates into the indoor air primarily through pores and cracks in the soil under a structure and/or the foundation of homes and other buildings. Usually, the air pressure is lower than the pressure outside in the soil around or underneath the foundation. The negative pressure differential will create suction, drawing radon up into the lower-level rooms. Radon levels are typically lower in spring and summer months when windows are often opened for ventilation but higher in the winter months when homes are heated, resulting in the warm air rising and drawing additional air up from the foundation into lower-level rooms that are typically sealed tighter during the winter to preserve the warmth (choice D is incorrect).