Impact of Combined Polycyclic Aromatic Hydrocarbon and Metal Exposure on Semen Quality: The Role of PAH–Metal Interactions

The objective of this study was to examine the interactions between 16 polycyclic aromatic hydrocarbons (PAHs) and six metals, namely the xenobiotic metals cadmium (Cd), lead (Pb), and arsenic (As) and the essential metals copper (Cu), zinc (Zn), and selenium (Se), in relation to semen quality and sperm DNA fragmentation. PAH exposure was assessed using personal breathing-zone measurements, whereas metal exposure was quantified by measuring urinary metal concentrations. Semen quality, including sperm concentration, motility, vitality, and morphology, was evaluated, and sperm DNA fragmentation was quantified using the terminal deoxynucleotidyl transferase dUTP nick-end labeling assay. Multiple linear regression models, with false discovery rate (FDR) adjustment, were used to examine whether PAH–metal interactions were associated with semen quality and sperm DNA fragmentation. Several associations between PAH–metal interactions and semen quality reached nominal statistical significance (praw < 0.05); however, none remained statistically significant after FDR correction (pFDR ≥ 0.05). In contrast, the interaction between Se and benzo[a]anthracene (B[a]A) in relation to sperm DNA fragmentation was statistically significant at both the nominal and FDR-adjusted levels. Se modified the association between B[a]A exposure and sperm DNA fragmentation, attenuating the increase in sperm DNA fragmentation associated with B[a]A exposure.