Exposure to fine particulate matter-bound polycyclic aromatic hydrocarbons, male semen quality, and reproductive hormones: The MARCHS study

Exposure to outdoor fine particulate matter (PM2.5)-bound polycyclic aromatic hydrocarbons (PAHs) is linked to reproductive dysfunction. However, it is unclear which component of PAHs is responsible for the adverse outcomes. In the Male Reproductive Health in Chongqing College Students (MARHCS) cohort study, we measured the exposure levels of 16 PAHs by collecting air PM2.5 particles and assessed eight PAHs metabolites from four parent PAHs, including naphthalene, fluorene, phenanthrene, and pyrene in urine samples. We investigated compositional profiles and variation characteristics for 16 PAHs in PM2.5, and then assessed the association between PAHs exposure and semen routine parameters, sperm chromatin structure, and serum hormone levels in 1452 samples. The results showed that naphthalene (95% CI: -17.989, -8.101), chrysene (95% CI: -64.894, -47.575), benzo[a]anthracene (95% CI: -63.227, -45.936) and all the high molecular weight (HMW) PAHs in PM2.5 were negatively associated with sperm normal morphology. Most of the low molecular weight (LMW) PAHs, such as acenaphthylene, fluorene, phenanthrene, fluoranthene, pyrene, chrysene, benzo[a]anthracene, Sigma LMW PAHs and Sigma 16 PAHs, were correlated with increased sperm motility (all corrected P <0.05). On the other hand, sperm normal morphology was all negatively associated with urinary metabolites of Sigma OH-Nap (95% CI: -5.611, -0.536), Sigma OH-Phe (95% CI: -5.741, -0.957), and Sigma OH-PAHs (95% CI: -5.274, -0.361). Urinary concentrations of Sigma OH-PAHs were found to be negatively associated with sperm high DNA stainability (HDS) (P = 0.023), while Sigma OH-Phe were negatively associated with serum testosterone level and sperm HDS (P = 0.004). Spearman correlation analysis showed that except for the urinary OH-Nap metabolites, the rest of the urinary OH-PAHs metabolites were negatively correlated with their parent PAHs in air. The results of this study suggest that various PAHs' components may affect reproductive parameters differently. Inhalation of PAHs in air, especially HMW PAHs, may be a potential risk factor for male reproductive health. (C) 2021 Elsevier Ltd. All rights reserved.