Organophosphate esters and their metabolites in Beijing total diets: Occurrence, time trend, and dietary exposure assessment.

Organophosphate esters (OPEs) and their metabolites (mOPEs) are emerging pollutants. In this study, 18 OPEs and 10 mOPEs were measured in the 6th and 7th Beijing total diet studies (TDSs), and the dietary intakes of these pollutants by Beijing adults were estimated to assess related health concerns. Most OPEs and mOPEs had high detecting frequencies in both TDSs, which indicated that various foods in Beijing have been universally contaminated with OPEs and mOPEs. Statistical analysis further confirmed that the levels of both ∑OPEs and ∑mOPEs in the 7th Beijing TDS were significantly higher than those in the 6th study, indicating heavier contamination of both OPEs and their metabolites with time. Along with increasing OPE/mOPE contamination level and food consumption values, significant increases of EDIs were observed during the two studies, with the average EDIs of ∑OPEs increasing from 5.07 to 24.1 ng/kg bw/day, and that of ∑mOPEs increasing from 2.07 to 7.23 ng/kg bw/day. Although a comparison between EDIs and reference of doses (RfDs) indicated that current intakes of OPEs could still not cause significant health risks, the sharply increasing contamination levels and EDIs suggested the necessity to continuously monitor these emerging food contaminants.