Brominated flame retardants in plasma samples from three different occupational groups in Norway

Brominated flame retardants (BFRs) are widely used in plastics, textile coa tings, electrical appliances and printed circuit boards to prohibit the dev elopment of fires. In order to investigate how exposure to BFRs is related to specific occupations, samples were obtained from Norwegian individuals w orking at an electronics dismantling facility, in the production of printed circuit boards, or as laboratory personnel. Nine BFRs were quantified in t he plasma samples: 2,4,4'-tribromodiphenyl ether (BDE-28), 2,2',4,4'-tetrab romodiphenyl ether (BDE-47), 2,2',4,4',5-pentabromodiphenyl ether (BDE-99), 2,2',4,4',6-pentabromodiphenyl ether (BDE-100), 2,2',4,4',5,5'-hexabromodi phenyl ether (BDE-153), 2,2',4,4',5,6'-hexabromodiphenyl ether (BDE-154), 2 ,2',3,4,4',5',6-heptabromodiphenyl ether (BDE-183), 2,4,6-tribromophenol (T riBP) and tetrabromobisphenol A (TBBP-A). The BFRs were extracted from plas ma using solid-phase extraction (SPE). The plasma lipids were decomposed by treatment with concentrated sulfuric acid directly on the SPE column, prio r to the elution of the BFRs. Following diazomethane derivatization, the sa mples were analysed by gas chromatography-electron capture mass spectrometr y. The subjects working at the electronics dismantling plant had significan tly higher plasma levels of TBBP-A and BDE-153 compared to the other groups , and the heptabrominated congener BDE-183 was only detected in plasma from this group. TriBP was generally the most abundant BFR present, and the pla sma concentrations were in the range 0.17-81 ng g(-1) lipids. BDE-47 was th e dominant BDE congener in all the individual samples and the levels were i n the range 0.43-14.6 ng g(-1) lipids. The total amounts of the seven BDEs were 8.8, 3.9 and 3.0 ng g(-1) lipids for the group of electronics dismantl ers, circuit board producers and laboratory personnel, respectively. Genera lly, large variations in the individual concentration levels were found wit hin the groups, especially in the group of electronics dismantlers, where t he relative standard deviations for BDE concentrations were in the range 23 -164%. The levels of BFRs were not correlated to age or the level of 2,2',4 ,4',5,5'-hexachlorobiphenyl (CB-153). The present work indicates that the p opulation in Norway is exposed to several BFRs, probably with food as a maj or source. The elevated level of higher brominated BDEs and TBBP-A in the p lasma from the workers at the dismantling plant suggests an additional occu pational exposure for these individuals. Thus, human exposure to BFRs seems to originate from a combination of different sources; however, further stu dies investigating plasma samples from a larger number of individuals are n ecessary for a more complete assessment of human exposure pathways to these environmental contaminants.