Abstract
BackgroundAlthough strong exposure to arsenic has been shown to be carcinogenic, its contribution to lung cancer incidence in the United States is not well characterized. We sought to determine if the low-level exposures to arsenic seen in the U.S. are associated with lung cancer incidence after controlling for possible confounders, and to assess the interaction with smoking behavior.MethodologyMeasurements of arsenic stream sediment and soil concentration obtained from the USGS National Geochemical Survey were combined, respectively, with 2008 BRFSS estimates on smoking prevalence and 2000 U.S. Census county level income to determine the effects of these factors on lung cancer incidence, as estimated from respective state-wide cancer registries and the SEER database. Poisson regression was used to determine the association between each variable and age-adjusted county-level lung cancer incidence. ANOVA was used to assess interaction effects between covariates.Principal FindingsSediment levels of arsenic were significantly associated with an increase in incident cases of lung cancer (P<0.0001). These effects persisted after controlling for smoking and income (P<0.0001). Across the U.S., exposure to arsenic may contribute to up to 5,297 lung cancer cases per year. There was also a significant interaction between arsenic exposure levels and smoking prevalence (P<0.05).Conclusions/SignificanceArsenic was significantly associated with lung cancer incidence rates in the U.S. after controlling for smoking and income, indicating that low-level exposure to arsenic is responsible for excess cancer cases in many parts of the U.S. Elevated county smoking prevalence strengthened the association between arsenic exposure and lung cancer incidence rate, an effect previously unseen on a population level.
Highlights
Arsenic has been linked to multiple cancer types including lung, bladder, kidney, liver, and skin cancers in numerous occupational, epidemiological, and experimental studies [1,2,3]
Median county income was negatively and significantly associated with incidence (P,0.0001), indicating that higher income was associated with reduced lung cancer incidence rates in the U.S Taken together, these results demonstrate that increased exposure to arsenic contributed to higher lung cancer incidence rates in the U.S, independent of smoking and socioeconomic status
In the joint analysis of arsenic exposure and smoking (Table 1), an increase of 1 ppm of arsenic concentration in the soil was associated with a 0.4% increase in the lung cancer incidence rate (OR: 1.004, 95% CI: [1.004–1.004])
Summary
Arsenic has been linked to multiple cancer types including lung, bladder, kidney, liver, and skin cancers in numerous occupational, epidemiological, and experimental studies [1,2,3]. Studies in Chile, Taiwan, and Bangladesh have established a clear association between arsenic and lung cancer. Tobacco smoke itself contains arsenic [4]. It is unclear what effect chronic low-level arsenic exposure has on lung cancer incidence rates in the U.S independent of and in conjunction with smoking on the population level. Strong exposure to arsenic has been shown to be carcinogenic, its contribution to lung cancer incidence in the United States is not well characterized. We sought to determine if the low-level exposures to arsenic seen in the U.S are associated with lung cancer incidence after controlling for possible confounders, and to assess the interaction with smoking behavior
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
