Increased health risk from co-exposure to polycyclic aromatic hydrocarbons, phthalates, and per- and polyfluoroalkyl substances: Epidemiological insight from e-waste workers in Hong Kong

The alarming surge in electronic waste (e-waste) in Hong Kong has heightened concerns regarding occupational exposure to a myriad of pollutants. Among these, polycyclic aromatic hydrocarbons (PAHs), phthalates (PAEs), and per- and polyfluoroalkyl substances (PFASs) are prevalent and known for their harmful effects, including the induction of oxidative stress and DNA damage, thereby contributing to various diseases. This study addresses gaps in knowledge by investigating exposure levels of these pollutants—measured via hydroxylated PAHs (OH-PAHs), phthalate metabolites (mPAEs), and PFASs—in urine from 101 e-waste workers and 100 office workers. E-waste workers exhibited higher concentrations of these substances compared to office workers. Elevated urinary levels of OH-PAHs, mPAEs, and PFASs correlated significantly with increased 8-hydroxy-2-deoxyguanosine (8-OHdG) levels (β = 2.53, 95 % CI: 2.12–3.02). The association between short-chain PFASs (Perfluoropentanoic acid, PFPeA) and DNA damage was discovered for the first time. Despite most participants (95 %) showing hazard index (HI) values below non-carcinogenic risk thresholds for PAHs and PAEs, certain pollutants posed higher risks among e-waste workers, necessitating enhanced protective measures. Moreover, the 95th percentile of carcinogenic risk associated with diethylhexyl phthalate (DEHP) exceeded 10⁻⁴ in both groups, highlighting the urgent need for regulatory measures to mitigate DEHP exposure risks in Hong Kong.