Does natural gas increase the indoor radon levels?

The natural gas is naturally occurring hydrocarbon which consists mainly of methane and includes varying amounts of other hydrocarbons, carbon dioxide and other impurities such as: nitrogen, and hydrogen sulfide. It is used domestically and industrially as a preferable energy source compared to coal and oil. Because natural gas is found in deep underground natural formations or associated with other underground hydrocarbon reservoirs, there is a potential to contain radon as a contaminant. This work was designated to measure indoor radon concentrations in dwellings supplied with natural gas compared with those not supplied with it, where radon level was estimated using solid state nuclear track detectors (CR-39). The results showed that radon concentration was significantly higher in dwellings supplied with natural gas, where it was 252.30 versus 136.19 Bq ⋅ m-3 in dwelling not supplied with natural gas (P < 0.001). The mean values of radon exhalation rate was 0.02 ± 6.34 ⋅ 10-4 Bq ⋅ m-2 ⋅ h-1 in dwellings supplied with natural gas and 0.01 ± 0.008 Bq ⋅ m-2 ⋅ h-1 in dwellings lacking it. In addition, a significant difference was observed in the mean annual effective doses (4.33 and 2.34 mSv ⋅ y-1, respectively) between both groups. Conclusively, the data indicate that natural gas may represent a potential source of indoor radon.