Co-exposure and interaction effect of a mixture of metals and polycyclic aromatic hydrocarbons on sperm oxidative damage

The study examined interactions between 16 polycyclic aromatic hydrocarbons (PAHs) and six metals in relation to sperm oxidative damage. PAH exposure was assessed using personal breathing-zone measurements, while metal exposure was quantified using urinary concentrations. Semen oxidative stress was evaluated by measuring reactive oxygen species (ROS) and malondialdehyde (MDA), and sperm oxidative DNA damage was assessed using 8-hydroxy-2'-deoxyguanosine (8-oxodGuo). Multiple linear regression models were used to examine whether interactions between metals and PAHs were associated with oxidative stress and sperm oxidative DNA damage. Cadmium (Cd) consistently interacted with PAH exposure in relation to ROS, MDA, and 8-oxodGuo levels. Notably, the interaction between Cd and acenaphthylene was significant in modifying 8-oxodGuo levels. Essential metals, including zinc (Zn), selenium (Se), and copper (Cu), also exhibited interactions with fluoranthene, naphthalene, and benzo[ghi]perylene, respectively. Dose-response trends consistently showed that the associations between PAHs and oxidative stress biomarkers were attenuated in the presence of these essential metals.