A retrospective study of PBDEs and PCBs in human milk from the Faroe Islands

BACKGROUND: Persistent organic pollutants (POPs) in wildlife and humans remain a cause of global concern, both in regard to traditional POPs, such as the polychlorinated biphenyls (PCBs), and emerging POPs, such as the polybrominated diphenyl ethers (PBDEs). To determine the time related concentrations, we analyzed human milk for these substances at three time points between 1987 and 1999. Polychlorobiphenylols (OH-PCBs), the dominating class of PCB metabolites, some of which are known to be strongly retained in human blood, were also included in the assessment. METHODS: We obtained milk from the Faroe Islands, where the population is exposed to POPs from their traditional diet (which may include pilot whale blubber). In addition to three pools, nine individual samples from the last time point were also analyzed. After cleanup, partitioning of neutral and acidic compounds, and separation of chemical classes, the analyses were carried out by gas chromatography and/or gas chromatography/mass spectrometry. RESULTS: Compared to other European populations, the human milk had high PCB concentrations, with pool concentrations of 2300 ng/g fat 1987, 1600 ng/g fat in 1994, and 1800 ng/g fat in 1999 (based on the sum of eleven major PCB congeners). The nine individual samples showed great variation in PCB concentrations. The OH-PCBs were present in trace amounts only, at levels of approximately 1% of the PCB concentrations. The PBDE concentrations showed a clear increase over time, and their concentrations in human milk from 1999 are among the highest reported so far from Europe, with results of individual samples ranging from 4.7 to 13 ng/g fat CONCLUSION: Although remote from pollution sources, the Faroe Islands show high concentrations of POPs in human milk, particularly PCBs, but also PBDEs. The PBDEs show increasing concentrations over time. The OH-PCB metabolites are poorly transferred to human milk, which likely is related to their acidic character

Retrospective time-trend study of polybrominated diphenyl ether and polybrominated and polychlorinated biphenyl levels in human serum from the United States.

Six polybrominated diphenyl ethers (PBDEs), one hexabromobiphenyl [polybrominated biphenyl (PBB)], and one hexachlorobiphenyl [polychlorinated biphenyl (PCB)] were measured in 40 human serum pools collected in the southeastern United States during 1985 through 2002 and in Seattle, Washington, for 1999 through 2002. The concentrations of most of the PBDEs, which are commercially used as flame retardants in common household and commercial applications, had significant positive correlations with time of sample collection, showing that the concentrations of these compounds are increasing in serum collected in the United States. In contrast, PCB and PBB levels were negatively correlated with sample collection year, indicating that the levels of these compounds have been decreasing since their phaseout in the 1970s

Organohalogen contaminants in humans with emphasis on polybrominated diphenyl ethers

The occurrence and distribution of organohalogen compounds, including polybrominated diphenyl ethers (PBDEs), in humans was investigated. For this purpose, the previously used method for analysis of organochlorine compounds was modified for the analysis of PBDEs and hydroxylated metabolites of polychlorinated biphenyls (OH-PCBs) in breast milk, matemal and cord blood plasma, liver and adipose tissue. PBDEs and PCBs were found in all samples. The PCB levels were approximately 100 times higher than those of PBDEs. Among the PBDEs, 2,2',4,4'-tetraBDE (BDE-47) was the predominant congener in breast milk, adipose tissue, matemal and cord blood, while in liver samples 2,2',4,4',5pentaBDE (BDE-99) occurred at similar concentrations as BDE- 47. The PCB congener profile was similar in all samples. 2,2',4,4',5,5'-hexaCB (CB-153), 2,2',3,4,4',5'-hexaCB (CB-138) and 2,2',3,4,4',5,5'-heptaCB (CB-180) were the dominant congeners. OH-PCBs constituted 30-50% of the sum of PCBs in blood samples, 1-10% in liver and 0.03-0.4% in adipose tissue, while the levels of OH-PCBs in breast milk were inconsiderable. Matrix specific differences were observed in OHPCB congener distribution. 2,2',3,4',5,5',6-heptachloro-4-biphenylol (4-OH-CB187) and 2,2',3,4',5,5'-hexachloro-4- biphenylol (4-0H-CB146) were the most dominant congeners in blood samples, 2,2',3,4,4',5'-hexachloro-3'-biphenylol (3'-OH-CB138) and 2,2',3,3',4,5'-hexachloro-4'-biphenylol (4'OH-CB130) in liver, 3´-OH-CB138 and 2,3,3',4',5,5',6-heptachloro-4-biphenylol (4-OH-CB 193) in adipose tissue. The presence of PBDEs, PCBs and OH-PCBs in cord blood demonstrates that placenta is not an effective barrier for the transfer of these compounds to the foetus. consequently, infants are exposed to organohalogen compounds already before they are born and additionally later via breast milk. Due to the low levels, postnatal exposure to OH-PCBs via breast milk in the present study subjects was considered of a minor importance. Temporal trends in contaminants have been investigated by analysing breast milk from different time periods. The levels of oganochlorine compounds: PCBs polychlorinated naphtalenes, dibenzo-rho-dioxins, dibenzofurans and several pesticides decreased to different extent from 1972 to 1997. During the same time period increasing levels of PBDEs were found. However, from 1998 to 2000 a decrease in PBDE levels was observed. The change in the trend was mainly due to the decrease of the most dominant PBDE congener, BDE-47. No large difference was noticed in levels of higher brominated PBDEs. During the same time period the levels of organochlorine contaminants in breast milk continued to decrease