Patterns of PCBs and OCPs exposure in a sample of Lebanese adults: The role of diet and physical activity.

Background: Exposure to persistent organic pollutants (POPs) in the general population is 90% from food intake. Dietary patterns provide a global estimation of exposure to POPs, taking into account multiple food sources of environmental contaminants.

Objectives: To evaluate the association of dietary, socio-demographic, anthropometric, and lifestyle-related variables with clusters of polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs), in a sample of students and employees of Saint Joseph University of Beirut.

Methods: A total of 302 participants were randomly recruited. Questionnaires covering dietary, socio-demographic, and lifestyle-related characteristics were administered. Anthropometric measurements were obtained. Serum concentrations of six indicator PCBs (PCB 28, 52, 101, 138, 153 and 180) and four OCPs, hexachlorobenzene (HCB), β-hexachlorocyclohexanes (β-HCH), p,p'-dichlorodiphenyltrichloroethane (DDT) and its metabolite p,p'-dichlorodiphenyldichloroethylene (DDE) were measured, and cluster analysis was applied. We evaluated the association of dietary intake with PCBs/OCPs exposure using two different approaches: food consumption categories and dietary patterns retrieved from principal component analysis (PCA).

Results: Three clusters of PCBs/OCPs were obtained: middle-level, high-level, and low-level. Practicing physical activity was associated with a three times higher risk of having high-level PCBs/OCPs, after adjustment for confounding variables (ORa = 2.97; CI = 1.23-7.19; p < 0.05). The highest tertile of fish and shellfish consumption increased by three-folds the odds of having high-level PCBs/OCPs (ORa = 3.41; CI = 1.07-10.84; p < 0.05). PCA revealed six dietary patterns. A "cereals, fats and oils, and eggs" dietary pattern was associated with 50% increase in the risk of having high-level PCBs/OCPs (ORa = 1.48; CI = 1.03-2.13; p < 0.05).

Conclusion: The present results offer a valuable contribution to the understanding of the factors increasing exposure to POPs, namely fish consumption and the "cereals, fats and oils, and eggs" dietary pattern. We also demonstrated that physical activity was positively associated with a higher risk of exposure to PCBs and OCPs, knowing that data on this matter are scarce.