Size-Resolved PM10-Bound PFASs: Respiratory Deposition and Association with Oxidative Stress Biomarkers Among Industrial Waste Recycling Workers

The global surge in industrial waste generation has raised substantial concerns regarding occupational exposure to per- and polyfluoroalkyl substances (PFASs) and the associated adverse health effects. However, critical knowledge gaps remain regarding the relationships among size-resolved airborne particulate matter (PM)-bound PFASs, internal exposure, and early-stage health damage. We conducted a panel study at a waste recycling plant in southern China, collecting 15 size-resolved PM samples and 280 repeated first morning void urine samples from 20 workers over 45 consecutive days. Relationship between size-resolved PM-bound PFASs, internal exposure, and oxidative stress biomarkers (OSBs:8-hydroxy-2′-deoxyguanosine (8-OHdG), malondialdehyde (MDA)) were analyzed using linear mixed-effects models. Our results indicate that short-chain PFASs predominated in both matrices. Intraclass correlation coefficients (ICCs) for urinary short-chain PFASs ranged from fair to excellent (ICC > 0.4). Notably, inhalation of PFASs in PM2.1–10 correlate more strongly with internal exposure than those in PM2.1. For the first time, we observed suggestive quantitative associations between OSBs and multiple short-chain PFASs in urine. More importantly, 8-OHdG levels were mainly correlated with PFASs in PM4.7–5.8 and PM9.0–10, with each unit increase in ln-transformed average daily intake (ADI) associated with a 10.2–12.6% increase in urinary 8-OHdG levels (p < 0.05). Similarly, MDA levels were primarily associated with PFASs bound to PM5.8–9.0, with each unit increase in ln-transformed ADI corresponding to an 8.0–14.6% increase in MDA (p < 0.05). These findings are exploratory and warrant further confirmation in independent cohorts. Nevertheless, this study highlights the need for more exposure monitoring and health impact assessments regarding PM2.1–10-bound short-chain PFASs among the occupational population.