Concentrations Of Halogenated Flame Retardants(HFRs) In Market Food And Indoor Dust In Nanjing:A Human Exposure Assessment

Polybrominated diphenyl ethers(PBDEs)have been gradually banned for use due to their persistent pollutant properties.As a substitute for PBDEs,emerging halogenated flame retardants(EHFRs)have been increasingly detected in the environment and the level of pollution,which has rised attention.Dietary exposure and dust intake are two potential ways in which the human body is exposed to halogenated flame retardants(HFRs).This study selected the economically developed and densely populated city,Nanjing,as target area to analyze the HFRs pollution levels in market food and indoor dust,and then assess the human exposure to HFRs.In this study,43 HFRs(including 27 PBDEs and 16 EHFRs)were selected as target substances.Ultra-trace analysis methods for HFRs in complex matrices were established and successfully applied to the quantitative detection of HFRs in food and dust.As presented,in the analysis of 9 types of market foods in Nanjing(n=105),the main pollutants in the food were BDE-17 and hexabromobenzene(HBBz)(mean concentrations as wet weight: 0.05 ng/g and0.018 ng/g,respectively),the pollution level of PBDEs is significant higher than EHFRs(t-test,p<0.05).For both PBDEs and EHFRs,the contamination level of plant foods is lower than that of animal foods(t-test,p<0.05).After that,analysis of the pollution distribution of HFRs in six indoor microenvironments(n=51)in Nanjing found that BDE-209(mean concentration 486.9ng/g)was the main pollutant.Consistent with food,the detection level of ∑PBDEs in dust is relatively high than ∑EHFRs.The overall level of HFRs in electronic maintenance centers is higher than in other places(AVONA,p<0.05).Based on the above test data,this study further investigated the dietary and dust exposure levels of specific populations in Nanjing by investigating the dietary habits and indoor activity patterns of those people in Nanjing(t-test,p<0.05),but the overall intake level does not exceed the EPA’s recommended intake threshold,indicating that the halogenated flame retardants ingested by those people through diet and dust will not pose a human health risk.However,due to the bioaccumulation characteristics of those compounds,continuous monitoring of those pollutants is also needed to fully assess their trends and possible exposure risks.