Seasonal variations and the prevalence of phenolic profiles in ambient fine particulate matter and their impact on oxidative potential.

Exposure to fine particulate matter (PM) poses numerous health risks, with oxidative potential (OP) serving as a critical marker of its toxicity. Synthetic phenolic antioxidants (SPAs) and bisphenols (BPs) influence reactive oxygen species (ROS) levels in PM, and exposure to these compounds induces oxidative stress in organisms, thereby potentially affecting the OP of PM. We detected 26 phenols (including 12 SPAs, 5 transformation products (TPs), and 9 BPs) in PM sample collected from October 2018 to September 2021 in Wuhan, China. Among them, 19 substances were detected at a detection frequency greater than 50 % in PM sample. AO 2246 and BHT were the main components of SPAs, and BHT-Q and BPA had the highest concentrations in TPs and BPs, respectively. PM mass concentrations and phenolic levels were higher in winter and autumn. Substances within groups were strongly correlated, suggesting the same or similar source of exposure. This finding aid in more precise pollution source identification and is crucial for comprehensively evaluating their combined health effects. Furthermore, we determined the OP of PM and found that BPs were related to increased OP and ROS. This suggests that the toxicity of PM is influenced not only by its concentration but also by its chemical composition, with BPs potentially enhancing its toxic effects. These factors should be fully considered when assessing the health impacts of PM.