Reducing lung cancer risk from radon exposure in Manheim Township, PA: Radon Resistant New Construction (RRNC) as a significant public health tool.

PURPOSE: Radon is a known human carcinogen and the second leading cause of lung cancer worldwide. This study evaluated the effectiveness of Radon Resistant New Construction (RRNC) ordinances enacted in Manheim Township, Pennsylvania, which mandate RRNC features in all new dwellings, to reduce lung cancer risk associated with radon exposure.

MATERIALS AND

METHODS

We identified new dwellings in Manheim Township built under RRNC ordinances and analyzed corresponding radon test and mitigation data from PA DEP databases. After carefully reviewing the data and correcting database reporting anomalies, we evaluated indoor radon levels with and without RRNC and estimated the average reduction. Finally, we employed an existing dose-response model to estimate the average reduction of lung cancer risk associated with RRNC, taking smoking status into consideration.

RESULTS

We analyzed 1,734 radon tests conducted in 483 homes, and found on average those homes built with RRNC features reduced the indoor radon concentration by 16.71 pCi/L and lowered the excess relative lung cancer risk attributable to radon exposure by 99%, regardless of smoking status.

CONCLUSIONS

Using real world data collected both before and after a change in municipal laws, these results provide strong evidence supporting the adoption of similar mandatory RRNC in other PA jurisdictions, nationwide, and in other countries that seek to reduce radon exposure and associated risks in indoor environment. This study demonstrates that the adoption and implementation of RRNC can reduce indoor radon levels, and consequently lower radon-related lung cancer risks.