PM2.5-bound plastic and rubber polymers from waste treatment facilities: Occurrence profiles and evidence of co-exposure to flame retardants.

Atmospheric PM2.5-bound plastic and rubber polymers are increasingly recognized as emerging contaminants amid concerns about inhalation exposure and potential health effects, yet their occurrence at waste treatment facilities remains poorly characterized. This study quantified 12 target polymers in PM2.5 samples collected from four waste treatment facilities (landfill, waste incineration plant, plastic recycling plant, and wastewater treatment plant) and an urban reference site using pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). Median total polymer concentrations followed: plastic recycling plant (8560 ng/m3) > landfill working area (964 ng/m3) > waste incineration plant (930 ng/m3) > wastewater treatment plant (646 ng/m3) > urban reference site (520 ng/m3). Polypropylene (PP) dominated at the plastic recycling plant (28-56%), while polyethylene (PE) predominated elsewhere (39-83%). Concentrations of ∑14HFRs at the plastic recycling plant ranged from 5.07 to 12.9 ng/m3 and were significantly correlated with PP (r = 0.75-0.86, p < 0.05), indicating their co-occurrence in workshop air. Estimated inhalation intake of PM2.5-bound target polymers for workshop workers (49.7-151 μg/day) substantially exceeded that for the general population, indicating elevated occupational inhalation exposure. These findings reveal facility-specific differences in atmospheric polymer profiles and potential co-exposure to plastic-associated chemicals, supporting targeted monitoring and occupational exposure management at waste treatment facilities.