title: Human exposure pathways to organophosphate triesters - a biomonitoring study of mother-child pairs.
abstract: The worldwide ban of several formulations of brominated flame retardants has caused an increase in the production of organophosphorus flame retardants (PFRs) to meet the existing fire regulations for a wide range of household products. This biomonitoring study surveys the occurrence of the metabolites from PFRs and related plasticizers (dialkyl and diaryl phosphates; DAPs) in urine from a Norwegian mother-child cohort (48 mothers and 54 children). Concentrations of DAPs were higher in the children than in their mothers (Wilcoxon signed-rank test p=0.001). Median urinary concentrations of diphenyl phosphate (DPHP) were 1.1 and 0.51ng/mL in children and mothers, respectively, followed by bis(1,3-dichloro-2-propyl) phosphate (BDCIPP) with medians of 0.23 and 0.12ng/mL, respectively. Detection frequencies for bis(2-butoxyethyl) phosphate (BBOEP) in urine from children and mothers were 32 and 1%, respectively (median<0.18ng/mL), and for di-n-butyl phosphate (DNBP) 15 and 8%, respectively (median<0.12ng/mL). The concentrations of DPHP and BDCIPP in urine from children were significantly correlated with those found for their parent compounds in air and dust from the households (Spearman's rank correlations 0.30<Rs<0.36; p<0.05). For mothers, only the urinary concentration of BDCIPP was correlated to its precursor in dust from the households (Rs=0.40; p<0.01), which might indicate higher impact of the household environment on children than mothers. A diurnal variability study of the mothers' urinary concentrations of DPHP and BDCIPP showed lower concentrations at time periods when women were likely to be outside the household. In contrast, no relevant associations between organophosphate metabolites in urine and food consumption data obtained through a 24hour recall were seen. This suggests that the residential environment is a more important exposure pathway to PFRs than the diet.
authors.affiliation: Department of Exposure and Risk Assessment, Norwegian Institute of Public Health, P.O. Box 4404, Nydalen, 0403 Oslo, Norway; Department of Analytical Chemistry and Organic Chemistry, Universitat Rovira i Virgili, Marcel·lí Domingo s/n, 43007 Tarragona, Spain. Electronic address: enrique.cequier@fhi.no.
authors.forename: Enrique
authors.initials: E
authors.lastname: Cequier
authors.affiliation: Department of Exposure and Risk Assessment, Norwegian Institute of Public Health, P.O. Box 4404, Nydalen, 0403 Oslo, Norway.
authors.forename: Amrit Kaur
authors.initials: AK
authors.lastname: Sakhi
authors.affiliation: Department of Analytical Chemistry and Organic Chemistry, Universitat Rovira i Virgili, Marcel·lí Domingo s/n, 43007 Tarragona, Spain.
authors.forename: Rosa Maria
authors.initials: RM
authors.lastname: Marcé
authors.affiliation: Department of Exposure and Risk Assessment, Norwegian Institute of Public Health, P.O. Box 4404, Nydalen, 0403 Oslo, Norway; Department of Chemistry, University of Oslo, P.O. Box 1033, Blindern, 0315 Oslo, Norway.
authors.forename: Georg
authors.initials: G
authors.lastname: Becher
authors.affiliation: Department of Exposure and Risk Assessment, Norwegian Institute of Public Health, P.O. Box 4404, Nydalen, 0403 Oslo, Norway.
authors.forename: Cathrine
authors.initials: C
authors.lastname: Thomsen
mesh_terms: D000328:Adult; D000393:Air Pollutants / Q000032:analysis* / Q000652:urine; D016902:Air Pollution, Indoor / Q000032:analysis; D002648:Child; D004391:Dust / Q000032:analysis*; D004784:Environmental Monitoring; D004952:Esters; D005260:Female; D005411:Flame Retardants / Q000032:analysis*; D005506:Food Contamination; D006798:Housing; D006801:Humans; D008297:Male; D008875:Middle Aged; D009035:Mothers; D009664:Norway; D010755:Organophosphates / Q000652:urine*; D010968:Plasticizers / Q000032:analysis*
chemical_list: D000393:Air Pollutants; D004391:Dust; D004952:Esters; D005411:Flame Retardants; D010755:Organophosphates; D010968:Plasticizers
keywords: Air; Dust; Flame retardants; Food; Metabolites; Urine