Association between polycyclic aromatic hydrocarbons (PAH) dietary exposure and mortality risk in the E3N cohort

Most studies have explored the adverse health effects of polycyclic aromatic hydrocarbons (PAH) occupational exposure. However, the general population is also exposed to PAH, mainly through the diet. The goal of the present study is thus to investigate the association between PAH dietary exposure and mortality risk in middle-aged women of the E3N (Étude Épidémiologique auprès de femmes de la mutuelle générale de l'Éducation Nationale) French prospective cohort. The study included 72,513 women, whom completed a validated semi-quantitative food frequency questionnaire on 208 food items in 1993. Food contamination levels were assessed using data provided by the Anses (French Agency for Food, Environmental and Occupational Health & Safety) in the framework of the French second total diet study. PAH dietary exposure was studied as the sum of four PAH (PAH4), namely benzo[a]pyrene (BaP), chrysene (CHR), benzo[a]anthracene (BaA) and benzo[b]fluoranthene (BbF). Cox proportional hazard models were used to estimate hazard ratios (HR) and their 95 % confidence intervals (CI) for the risk of all-cause mortality as well as all-cancer, specific cancer (separately from breast, lung/tracheal, and colorectal cancer), cardiovascular disease (CVD), and specific CVD (including only stroke and coronary heart disease) mortality. During follow-up (1993-2011), 4620 validated deaths were reported, of which 2726 due to cancer and 584 to CVD. The median PAH4 dietary intake was 66.1 ng/day. There was no significant association between PAH4 dietary intake and the risk of all-cause, all-cancer, breast cancer, colorectal cancer, all-CVD and stroke and coronary heart disease mortality. On the contrary, we observed a positive and statistically significant association between PAH4 dietary intake and lung/tracheal cancer mortality risk, with a stronger association among current smokers than among former smokers and never smokers. In this study, we observed an association between PAH dietary exposure and lung/tracheal cancer mortality risk, especially among current smokers.