Human exposure to persistent organic pollutants in Switzerland: The role of diet, age, smoking, and body composition

Persistent organic pollutants (POPs), including polychlorinated dibenzo-p-dioxin/dibenzofuran (PCDD/Fs) and polychlorinated biphenyls (PCBs), are widespread environmental contaminants that bioaccumulate in human, primarily through dietary intake. We conducted a cross-sectional study performed in Lausanne, Switzerland to investigate the association between the serum concentrations of POPs and individual characteristics. We measured 17 PCDD/Fs, 12 dl-PCBs and 6 i-PCBs in 80 volunteers. Participants provided demographic and lifestyle data and completed a food frequency questionnaire. Geometric mean concentrations were 6.2 pgTEQ/g lipid for PCDD/Fs, 4.2 pgTEQ/g lipid for dl-PCBs and 117.3 ng/g lipid for i-PCBs. Age, body fat mass, smoking status were statistically associated with serum concentrations. Dietary associations were congener-specific; notably, egg consumption correlated with higher PCDF concentrations, and plant-based foods were, unexpectedly, linked to increased overall POP levels. Active smoking was associated with higher PCB serum concentrations. We highlighted divergent association (smoking status or body fat mass) between PCDD/Fs and PCBs although they share similar physico-chemical properties. The ubiquity of pollutants in the environment has led to their widespread presence in human body, despite stringent regulation. There is an urgent need to investigate the food contamination origin to reduce the general population exposure to environmental pollutants.