Halogenated And Organophosphate Flame Retardant In House Dust From Guangzhou: Concentrations,size-dependent Distributions And Human Expousre Assessment

Polybrominated diphenyl ethers(PBDEs),novel halogenated flame retardants(NHFRs)and organophosphate flame retardants(OPFRs)are widely used in commercial and household proudcts worldwide.Many of them are persistent,biaoccumulative,and toxic.As most additive flame retardants can migrate from host products and bind with indoor dust,indoor dust becomes one of the most important vector for human exposure to flame retardants.Our study investigated the compositions,concentrations,and size-depednent distributions of a suite of flame retardants in indoor dust from 30 dwellings in Guangzhou(China).Main conclusions are listed below.In the studied indoor dust,concentrations of PBDEs,NHFRs,and OPFRs ranged from 0.11 to 18.61 ? g/g,1.01–59.85 ? g/g,and 1.62–60.29 ? g/g,respectively.BDE209 was the dominant PBDE congener,while the BDE209 replacement,(Decabromodiphenylethane)DBDPE,was the most abundant NHFR and its concentrations surpassed Decabrominated diphenyl ether(BDE209)in many samples.Other NHFRs,incluing Pentabromobenzene(PBBZ),Pentabromobenzyl bromide(PBBB),Hexabromobenzene(HBBZ),2-Ethylhexyl-2,3,4,5-tetrabromobenzoate(EH-TBB),1,2-Bis-(2,4,6-TribromoPhen-oxy)ethane(BEH-TEBP),and 1,2-Bis-(2,4,6-tribromophenoxy)ethane(BTBPE),DBDPE were also frequently detected.OPFRs were dominated by chlorinated substances in our study,different from the patterns observed in most other studies.A few novel OPFRs,incluing Bisphenol A(BPADP),Isodecyl diphenyl phosphate(ISO_DDPP),Cresyl diphenyl phosphate(CDP),Dimethyl phosphate(RDP)were also frequently detected in Guangzhou indoor dust.Flame retardants were not evenly distributioned among dust particles with different sizes.The main flamer retardants in indoor dust,including BDE209,DBDPE,and a number of OPFRs,were present in particles with granular sizes less than 125? m at greater levels than in particles with sizes > 250 ? m.Octanol-water and octanol-air partition coefficients(Kow and Koa)both significantly influencedsize-distribution of flame retardants.The substances with log Kow > 10 and log Koa > 16 were more prone to accumulate in fine particles and exhibited greater inter-size concentration differences.The estimated intake rates of NHFRs and OPFRs were approximately one order of magnitude greater than those for PBDEs.Children are subjected to elevated exposure compared with adults.The estimated intake rates of flame retardants via indoor dust in Guangzhou were generally 2-4 order of magnitude lower than the reference doses.However,the health risks via dust intake should not be overlooked,given that additive or synergistic effects may be existing between flame retardants or between flame retadants and other toxic chemicals present in house dust.