Relationship between radon exposure and lung cancer prevalence in selected counties in Colorado, New Mexico, and Texas

Introduction: Residential radon (RR) exposure is the second leading cause of lung cancer. Smoking amplifies the risk of developing lung cancer due to RR exposure. Despite public health campaigns and free testing programs, RR causes an estimated 22,000 lung cancer deaths in the United States yearly. The present study was undertaken to analyze lung cancer rates between counties in New Mexico, Colorado, and Texas based on predicted average levels (PAL) of RR.

Methods: Data pertaining to radon levels, lung cancer rates, and smoking was collected from several state, county, and federal sources. Counties were selected based on their smoking rates and government-designated PAL of RR. Data was analyzed using a variety of statistical measures to determine whether there existed a significant statistical difference between lung cancer rates and PAL of RR.

Results: Analysis revealed a statistically significant difference in county rates of lung cancer by predicted radon exposure level (F=10.21, p-value < 0.0002). However, the rate of lung cancer in counties with a low PAL of RR was significantly higher than that in counties with a high PAL of RR. Texas counties had significantly higher lung cancer rates (F= 14.73, p-value< 0.0001) than New Mexico and Colorado counties.

Conclusions: The results of the present study suggest a significant confounding variable leading to increased lung cancer rates other than smoking or radon; this in turn highlights the need to consider multiple etiological factors when studying the relationship between RR exposure and lung cancer.