Lotta Hovander

Fetal Exposure to PCBs and Their Hydroxylated Metabolites in a Dutch Cohort

Polychlorinated biphenyls (PCBs) are still the most abundant pollutants in wildlife and humans. Hydroxylated PCB metabolites (OH-PCBs) are known to be formed in humans and wildlife. Studies in animals show that these metabolites cause endocrine-related toxicity. The health effects in humans have not yet been evaluated, especially the effect on the fetus and newborn. The aim of this study is to measure the levels of PCBs and OH-PCBs in maternal and cord blood samples in a population with background levels of PCBs. We analyzed 51 maternal and corresponding cord blood samples in the northern part of the Netherlands. The PCB concentrations in maternal plasma ranged from 2 to 293 ng/g lipid, and OH-PCB concentrations from nondetectable (ND) to 0.62 ng/g fresh weight. In cord plasma, PCB concentrations were 1–277 ng/g lipid, and OH-PCB concentrations, ND to 0.47 ng/g fresh weight. The cord versus maternal blood calculated ratio was 1.28 ± 0.56 for PCBs and 2.11 ± 1.33 for OH-PCBs, expressed per gram of lipid. When expressed per gram fresh weight, the ratios are 0.32 ± 0.15 and 0.53 ± 0.23 for PCBs and OH-PCBs, respectively. A significant correlation between the respective maternal and cord levels for both PCBs and OH-PCBs was found. Our results indicate that OH-PCBs and PCBs are transferred across the placenta to the fetus in concentrations resulting in levels of approximately 50 and 30%, respectively, of those in maternal plasma. More research in humans is needed to evaluate potential negative effects of these endocrine disruptors on the fetus.

Significantly Higher Polybrominated Diphenyl Ether Levels in Young U.S. Children than in Their Mothers

While young children are rarely included in biomonitoring studies, they are presumed to be at greater risk of ingesting environmental contaminants-particularly those that accumulate in foods or shed from consumer products. The widely used fire retardants polybrominated diphenyl ethers (PBDEs) are ubiquitous contaminants in the indoor environment and are widely detected at higher levels in Americans than in individuals from other countries. However, there are only three studies of PBDEs in U.S. children. We hypothesized that PBDEs are present in higher concentrations in young children than their mothers. PBDEs were assessed in blood samples collected concurrently from 20 mothers and their children, ages 1.5 to 4 years. The chemical analyses were performed by GC/MS applying selected ion monitoring. The samples were analyzed for 20 PBDE congeners; 11 were detected. SigmaPBDEs for children were typically 2.8 times higher than for mothers, with median child:mother ratios varying from 2 to 4 for individual congeners. In 19 of 20 families studied, children had higher SigmaPBDE concentrations than their mothers with significant (p < 0.01) concentration differences for five of the PBDE congeners. Decabromodiphenyl ether (BDE-209) was quantitated in 13 children and 9 mothers. Other studies indicate PBDEs are not elevated at birth, suggesting that early life is an intense period of PBDE intake. Childrens increased hand-to-mouth activity, dietary preferences, and exposures from breast milk may result in greater ingestion of PBDEs than adults. These findings suggest that measurements from adults likely do not reflect exposures to young children despite sharing homes and similar diets.

Polybrominated diphenyl ethers in aircraft cabins – a source of human exposure

Commercial aircrafts need a high degree of fire protection for passenger safety. Brominated flame retardants (BFRs), including polybrominated diphenyl ethers (PBDEs), may be used for this purpose. Because PBDEs readily absorb to dust particles, aircraft crew and passengers may receive significant PBDEs exposure via inhalation. The aims of this work were to assess whether PBDEs could be found in aircraft cabin dust and whether serum levels of PBDEs increased in passengers after long-distance flights. Hence nine subjects on intercontinental flights collected cabin dust samples, as well as donated blood samples before departure and after return to Sweden. Two subjects who were domestic frequent flyers were also investigated. The levels of PBDEs in dust and serum were determined by GC/MS in electron capture negative ionization (ECNI) mode. Authentic reference substances were used for identification and quantitation. PBDEs were found in all aircraft dust samples at high concentrations, higher than in common household dust. Congener patterns indicated that the technical products PentaBDE, OctaBDE and DecaBDE were used in the aircrafts. Serum concentrations in the travellers were similar to those observed in Swedish residents in general. Post-travel serum levels of BDE-28, BDE-99, BDE-100, BDE-153, and BDE-154 were significantly higher (p<0.05) than concentrations prior to travel. The findings from this pilot study call for investigations of occupational exposures to PBDEs in cabin and cockpit crews.

Recovery discrepancies of OH-PBDEs and polybromophenols in human plasma and cat serum versus herring and long-tailed duck plasma

Hydroxylated polybrominated diphenyl ethers (OH-PBDEs) have been identified as metabolites of polybrominated diphenyl ethers (PBDEs) and/or as natural products. The OH-PBDEs and polybromophenols have come into focus over the last decade due to their abundance in biota and their potential adverse health effects. The present recovery study aims to validate a commonly used method (published by Hovander et al. 2000) for OH-PBDE analysis in human plasma. Further, the authors intended to determine the methods applicability to serum/plasma matrices from other species than humans. The investigated matrices were human plasma, cat serum, herring- and long-tailed duck plasma. The recovery study included nine OH-PBDEs, four polybromophenols and three methoxylated PBDEs (MeO-PBDEs). Five replicates of each matrix were spiked with these compounds at two dose levels; a low dose (0.5 ng) and a high dose (5 ng) and were cleaned up according to the Hovander method. The recovery of OH-PBDEs and polybromophenols in human plasma and cat serum were high and reproducible at both dose levels whereas the recovery for herring and long-tailed duck plasma were low and insufficient with great variability amongst OH-PBDE congeners at both dose levels. Our data show that the method can be fully applied to matrices like human plasma and cat serum but not for herring and long-tailed duck plasma without further method development. Hence care needs to be taken when applying the method onto other blood matrices without validation since the present study have demonstrated that the recoveries may differ amongst OH-PBDE congeners and specie.