Levels, influencing factors, sources and exposure assessment of organophosphate esters in fine particulate matter and total suspended particle from Nanjing, China

Organophosphate esters (OPEs) have garnered significant attention for their extensive environmental presence and potential risk to biota, including humans. This study investigated the levels, influencing factors, sources and health risks of OPEs partitioning in atmospheric fine particulate matters (PM _2.5 ) and total suspended particles (TSP) from Nanjing, China. The total concentrations of eleven OPEs (detection frequency > 50%) in PM _2.5 and TSP were range of 57.0 − 404 pg/m ³ and 37.7 − 354 pg/m ³ . OPEs tended to partition into fine particles for their higher adsorption capacity and octanol-air partition coefficient ( K _OA ) of OPEs. Meteorological factors such as temperature and air pressure had opposite effects on halogenated and aryl OPEs, with high temperatures and low pressures causing halogenated OPEs to volatilize and partition into particles. Air mass trajectory analysis indicated differing sources for particulate matter and OPEs, with particulate matter originating mainly from Anhui, Jiangsu, Zhejiang, Henan, Jiangxi and Hubei provinces, and OPEs primarily from Jiangxi, Zhejiang and Shandong provinces. Correlation analysis and principal component analysis identified building constructions, traffic emissions and foam products, and indoor emissions as OPEs sources. The non-cancer risk assessment indicated no potential risk of concern, as the evaluation by hazard quotient was far below the acceptable risk.