title: Assessment of human hair as an indicator of exposure to organophosphate flame retardants. Case study on a Norwegian mother-child cohort.
abstract: A major challenge of non-invasive human biomonitoring using hair is to assess whether it can be used as an indicator of exposure to Flame Retardants, such as Organophosphate Flame Retardants (PFRs), since the contribution of atmospheric deposition (air and/or dust) cannot be neglected. Therefore, the aim of this study was to evaluate the suitability of using human hair more thoroughly by comparison of (i) levels of PFRs in human hair (from 48 mothers and 54 children), with levels measured in dust and air in their respective households; and (ii) levels of selected PFRs in hair with the levels of corresponding PFR metabolites in matching urine samples collected simultaneously. Most PFRs (tri-n-butyl phosphate (TNBP), 2-ethyl-hexyldiphenyl phosphate (EHDPHP), tri-phenyl phosphate (TPHP), tri-iso-butyl phosphate (TIBP), and tris(2-butoxyethyl) phosphate (TBOEP)) were detected in all human hair samples, tris(2-ethylhexyl) phosphate (TEHP) and tris(1,3-dichloro-iso-propyl) phosphate (TDCIPP) in 93%, tri-cresyl-phosphate (TCP) in 69% and tris(2-chloroethyl) phosphate (TCEP) in 21% of the samples. Levels of individual PFRs ranged between <1 and 3744 ng/g hair and were lower than in indoor dust from the participants' homes. Several statistically significant associations between PFR levels in human hair and PFR levels in house dust and/or air were found, e.g. Spearman correlation (rS = 0.561, p < 0.05) between TBOEP in children's hair and in indoor air. Also, associations were found between TDCIPP in hair and its metabolite bis(1,3-dichloro-iso-propyl) phosphate (BDCIPP) in urine; they were stronger for children (e.g. Pearson correlation rP = 0.475; p = 0.001) than for mothers (rP = 0.395, p = 0.01). Levels of diphenyl phosphate (DPHP) in mothers' and children's urine were slightly correlated (rS = 0.409, p = 0.008), suggesting similar sources of exposure. To the best of our knowledge, this is the first study with such design and our findings might help to understand human exposure to and body burdens of PFRs.
authors.affiliation: VITO - Flemish Institute for Technological Research, Boeretang 200, 2400 Mol, Belgium; University of Antwerp, Toxicological Centre, Campus Drie Eiken, Universiteitsplein 1, 2610 Wilrijk, Belgium.
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Kucharska
authors.affiliation: NIPH - Norwegian Institute of Public Health, P.O. Box 4404, Nydalen, 0403 Oslo, Norway.
authors.forename: Enrique
authors.initials: E
authors.lastname: Cequier
authors.affiliation: NIPH - Norwegian Institute of Public Health, P.O. Box 4404, Nydalen, 0403 Oslo, Norway.
authors.forename: Cathrine
authors.initials: C
authors.lastname: Thomsen
authors.affiliation: NIPH - Norwegian Institute of Public Health, P.O. Box 4404, Nydalen, 0403 Oslo, Norway.
authors.forename: Georg
authors.initials: G
authors.lastname: Becher
authors.affiliation: University of Antwerp, Toxicological Centre, Campus Drie Eiken, Universiteitsplein 1, 2610 Wilrijk, Belgium.
authors.forename: Adrian
authors.initials: A
authors.lastname: Covaci
authors.affiliation: VITO - Flemish Institute for Technological Research, Boeretang 200, 2400 Mol, Belgium. Electronic address: stefan.voorspoels@vito.be.
authors.forename: Stefan
authors.initials: S
authors.lastname: Voorspoels
mesh_terms: D000293:Adolescent; D000328:Adult; D000393:Air Pollutants / Q000378:metabolism*; D002648:Child; D004391:Dust / Q000032:analysis*; D004784:Environmental Monitoring; D005260:Female; D005411:Flame Retardants / Q000378:metabolism*; D006197:Hair / Q000737:chemistry; D006801:Humans; D008297:Male; D018811:Maternal Exposure; D008875:Middle Aged; D009664:Norway; D010755:Organophosphates / Q000378:metabolism*
chemical_list: D000393:Air Pollutants; D004391:Dust; D005411:Flame Retardants; D010755:Organophosphates
keywords: Exposure assessment; Hair analysis; Organophosphate flame retardants; Urine