Rhee J, et al. - Whether and how blood lead levels (BLLs) are related to lung cancer mortality was clarified by performing an updated analysis within NHANES II and III with mortality linkage extended through December 2014. Post-adjustment for smoking (both surveys) and serum cotinine as well as environmental tobacco smoke exposure (NHANES III), no overall link between BLLs and lung cancer was found, although suggestive links were noted in women. Overall, experts observed a link between increased BLLs and lung cancer mortality in females in both NHANES II and III. Given the absence of a link in non-smokers, experts cannot rule out residual confounding as an explanation for these revelations.