• Home
  • Search Results
  • Assessment of human hair as an indicator of exposure to organophosphate flame retardants. Case study on a Norwegian mother-child cohort.

Assessment of human hair as an indicator of exposure to organophosphate flame retardants. Case study on a Norwegian mother-child cohort.

Environment international (2015-06-18)
Agnieszka Kucharska, Enrique Cequier, Cathrine Thomsen, Georg Becher, Adrian Covaci, Stefan Voorspoels
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.

MATERIALS
Product Number
Brand
Product Description

Sigma-Aldrich
Methanol, anhydrous, 99.8%
Sigma-Aldrich
Dichloromethane, anhydrous, ≥99.8%, contains 40-150 ppm amylene as stabilizer
Sigma-Aldrich
Toluene, anhydrous, 99.8%
Sigma-Aldrich
Sulfuric acid, 99.999%
Sigma-Aldrich
Hexane, anhydrous, 95%
Sigma-Aldrich
Hydrochloric acid solution, 1.0 N, BioReagent, suitable for cell culture
Sigma-Aldrich
Hydrochloric acid, 36.5-38.0%, BioReagent, for molecular biology
Sigma-Aldrich
Nitric acid, 70%, purified by redistillation, ≥99.999% trace metals basis
Supelco
Hydrochloric acid solution, volumetric, 0.1 M HCl (0.1N), endotoxin free
Sigma-Aldrich
Nitric acid, ACS reagent, ≥90.0%
Sigma-Aldrich
Dichloromethane, suitable for HPLC, ≥99.9%, contains 40-150 ppm amylene as stabilizer
Sigma-Aldrich
Hydrogen chloride, ReagentPlus®, ≥99%
Sigma-Aldrich
Hydrochloric acid solution, ~6 M in H2O, for amino acid analysis
Sigma-Aldrich
Hydrogen chloride solution, 3 M in cyclopentyl methyl ether (CPME)
Sigma-Aldrich
Hydrochloric acid solution, 32 wt. % in H2O, FCC
Sigma-Aldrich
Sodium sulfate, ≥99.99% trace metals basis
Sigma-Aldrich
Sodium sulfate, BioXtra, ≥99.0%
Sigma-Aldrich
Sodium sulfate, BioUltra, anhydrous, ≥99.0% (T)
Supelco
Methanol solution, NMR reference standard, 4% in methanol-d4 (99.8 atom % D), NMR tube size 5 mm × 8 in.
Sigma-Aldrich
Sodium sulfate, ≥99.0%, suitable for plant cell culture
Sigma-Aldrich
Methanol, NMR reference standard
Sigma-Aldrich
Methanol solution, NMR reference standard, 4% in methanol-d4 (99.8 atom % D), NMR tube size 3 mm × 8 in.
Sigma-Aldrich
Nitric-14N acid solution, ~10 N in H2O, 99.99 atom % 14N
Sigma-Aldrich
Methanol-12C, 99.95 atom % 12C