Polybrominated Diphenyl Ethers Exposure Research Articles

Thyroid Insult: Flame Retardants Linked to Alterations in Pregnant Women’s TSH Levels

Vol. 118, No. 10 NewsOpen AccessThyroid Insult: Flame Retardants Linked to Alterations in Pregnant Women’s TSH Levels Kellyn S. Betts Kellyn S. Betts Search for more papers by this author Published:1 October 2010https://doi.org/10.1289/ehp.118-a445bAboutSectionsPDF ToolsDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InReddit Polybrominated diphenyl ether (PBDE) flame retardants have been added to a wide variety of U.S. consumer goods including automobiles, airplanes, electronics, home furnishings, and furniture. Although two forms of PBDEs were phased out of use by 2004, data from the Centers for Disease Control and Prevention suggest exposure to these persistent, bioaccumulative, potentially toxic compounds remains widespread among the general U.S. population. New research now links higher exposure to PBDEs with reduced levels of thyroid-stimulating hormone (TSH) and higher rates of subclinical hyperthyroidism in women [EHP 118(10):1444–1449; Chevrier et al.]. The findings may have implications for maternal health and fetal development.Thyroid hormones are known to play an essential role in fetal brain development, and altered maternal thyroid hormone levels may adversely affect child neurodevelopment. The authors cite multiple animal studies showing that PBDEs alter pregnant rodents’ thyroid functioning. In the last year, laboratory tests using human cells suggested that PBDEs may affect brain development and linked the alterations to disruptions in thyroid hormone signaling. Recent research also has linked higher PBDE exposure to reduced intelligence in children.The authors believe their new study to be the largest to analyze associations between PBDEs and thyroid hormone during pregnancy. The 270 study participants were pregnant in 1999 and 2000 when they were recruited for the Center for Health Assessment of Mothers and Children of Salinas (CHAMACOS) study. The research team measured the women’s thyroid hormone levels, then evaluated the data with models that adjusted for potential confounding factors, such as demographic characteristics and exposure to other persistent, bioaccumulative, and toxic compounds.Women with higher blood PBDE levels had lower levels of TSH. The women with the highest levels of PBDEs were more likely to have lower TSH but normal levels of the thyroid hormone thyroxine (T4), suggesting subclinical hyperthyroidism. The combination of lower TSH and “normal” T4—as defined by the reference range applied to lab results—could mean an individual’s T4 levels actually are elevated above her body’s “set point” (or optimal level) of T4, which varies from person to person.Most human studies in this area have associated increased exposure to PBDEs with elevated free T4. The only other study known to examine PDBEs and thyroid hormone specifically in pregnant women—which included only nine women—did not find increased T4, but the authors did not examine TSH levels. In contrast, other studies of pregnant women’s thyroid hormone levels have linked higher exposure to organochlorine pesticides and polychlorinated biphenyls—which have chemical structures and properties similar to those of PBDEs—with increased TSH and decreased T4.FiguresReferencesRelatedDetails Vol. 118, No. 10 October 2010Metrics About Article Metrics Publication History Originally published1 October 2010Published in print1 October 2010 Financial disclosuresPDF download License information EHP is an open-access journal published with support from the National Institute of Environmental Health Sciences, National Institutes of Health. All content is public domain unless otherwise noted. Note to readers with disabilities EHP strives to ensure that all journal content is accessible to all readers. However, some figures and Supplemental Material published in EHP articles may not conform to 508 standards due to the complexity of the information being presented. If you need assistance accessing journal content, please contact [email protected]. Our staff will work with you to assess and meet your accessibility needs within 3 working days.

PBDE Concentrations in Women: Harley et al. Respond

In our study (Harley et al. 2010), we found statistically significant associations between higher PBDE (polybrominated diphenyl ether) concentrations in women and longer time to achieve pregnancy. According to Goodman et al., we stated that the association of PBDEs and fecundability is likely causal. We never made this claim. As with all observational studies, associations do not guarantee causation. However, we believe this is a well-conducted study with a strong design to investigate the potential effects of PBDEs on time to pregnancy. Goodman et al. argue that errors in the measurement of PBDE exposure or in recall of time to pregnancy could bias our results. We agree that little is known about the degree to which PBDE levels vary over time. However, we have no reason to believe that this variability would lead to differential misclassification with regard to the outcome. Similarly, women were blinded as to their PBDE levels, so we have no reason to believe that recall of time to pregnancy was biased. In both cases, measurement error would likely bias our results towards the null, making our results conservative. Goodman et al. also questioned the appropriateness of our statistical model. The authors correctly point out that a key assumption of the discrete-time Cox proportional hazards model is that the hazard ratio [or, in this case, fecundability odds ratio (fOR)] be constant over the follow-up time. When this assumption is not met, the reported fOR represents a weighted average of the estimate in each month of trying to become pregnant, and may be biased for the exposure effect at a specific time. We tested the proportionality assumption by examining the odds of becoming pregnant in each discrete month when no contraception was used. Although the magnitude of the association was slightly less in the first month of follow-up compared with later months, we found that higher PBDE concentration was associated with decreased fecundability in every month. Goodman et al. were also concerned about uncontrolled confounding. Although it is true that many factors affect the timing of pregnancy, confounding is present only when these factors are associated with the exposure as well as the outcome. We have no reason to believe that the factors mentioned by Goodman et al. would be associated with PBDE levels, other than by chance. We did evaluate many of the factors they listed (i.e., frequency of intercourse, alcohol consumption, smoking, and drug use) and reported that they did not confound our results. Although we agree that one can never control for all possible confounding factors in an observational study—this is an inherent limitation of epidemiology—we have taken care to minimize confounding as much as possible. Finally, Goodman et al. argue that limiting the study to pregnant women could bias results away from the null. We cannot think of a circumstance in which this would be true. The inherent selection bias of retrospective studies in pregnant populations is that infertile couples are excluded and subfertile couples are underrepresented. Thus, if there is a true association between PBDEs and time to pregnancy, then limiting the study to the most fertile couples will reduce statistical power and lead to an underestimation of the effect. However, if there is no association between PBDEs and time to pregnancy, then we would expect the fOR to be 1.0 among all women. Overrepresenting the most fertile couples would continue to show a null effect. We fail to see how excluding subfertile women would bias findings away from the null or show a spurious association. Time-to-pregnancy studies are methodologically complicated, and both prospective and retrospective studies have their limitations. For a detailed discussion of the biases in retrospective study designs, as well as a discussion of how to minimize them, see Joffe et al. (2005). A strength of our study is that we undertook multiple sensitivity analyses to investigate the extent that our findings changed when inclusion criteria or details of the analytic methods were altered. Our findings remained largely unchanged in all these sensitivity analyses. In summary, the limitations pointed out by Goodman et al. would serve to underestimate our estimate of effect, not inflate it. However, since this is the first study of PBDE exposure and time to pregnancy, our findings need to be replicated in other populations.

PBDE exposure from food in Ireland: optimising data exploitation in probabilistic exposure modelling

Polybrominated diphenyl ethers (PBDEs) are a class of brominated flame retardants added to plastics, polyurethane foam, electronics, textiles, and other products. These products release PBDEs into the indoor and outdoor environment, thus causing human exposure through food and dust. This study models PBDE dose distributions from ingestion of food for Irish adults on congener basis by using two probabilistic and one semi-deterministic method. One of the probabilistic methods was newly developed and is based on summary statistics of food consumption combined with a model generating realistic daily energy supply from food. Median (intermediate) doses of total PBDEs are in the range of 0.4-0.6 ng/kg(bw)/day for Irish adults. The 97.5th percentiles of total PBDE doses lie in a range of 1.7-2.2 ng/kg(bw)/day, which is comparable to doses derived for Belgian and Dutch adults. BDE-47 and BDE-99 were identified as the congeners contributing most to estimated intakes, accounting for more than half of the total doses. The most influential food groups contributing to this intake are lean fish and salmon which together account for about 22-25% of the total doses.

Polybrominated Diphenyl Ether (PBDE) Levels in Peregrine Falcon (Falco peregrinus) Eggs from California Correlate with Diet and Human Population Density

Peregrine falcons are now considered a conservation success story due in part to the phasing out of harmful contaminants that adversely affected reproduction. Recent studies have shown that peregrine eggs collected from California cities, however, have high levels of the higher-brominated polybrominated diphenyl ethers (SigmaPBDE(183-209)), a class of industrial flame retardants, in comparison to published data for other wildlife. Sources of these high PBDE levels and unusual PBDE profiles are unknown. Here we analyzed the stable carbon (delta(13)C), hydrogen (deltaD), and nitrogen (delta(15)N) isotope composition of peregrine eggs collected from urban and nonurban habitats. We found that delta(13)C values were significantly higher in urban versus nonurban eggs, suggesting that urban peregrines indirectly receive anthropogenic subsidies via their consumption of prey reliant on corn-based anthropogenic foods. delta(15)N and deltaD values were significantly lower in urban versus nonurban eggs, reflecting differences in dietary diversity and food/water sources available to peregrines in each habitat. These patterns suggest a link between an anthropogenic diet and high levels of SigmaPBDE(183-209) in California peregrines, and identify anthropogenic food as a potentially important PBDE exposure pathway for urban wildlife. If diet is an important PBDE exposure pathway for peregrines, continued high body burdens of SigmaPBDE(183-209) may be a potential risk to ongoing peregrine conservation efforts in California.

Impact of non-occupational exposure to polybrominated diphenyl ethers on menstruation characteristics of reproductive-age females

Polybrominated diphenyl ethers (PBDEs) have documented effects on thyroid functions and rodent behavior in vivo. Epidemiological studies, however, have revealed only limited information about associations between PBDE exposure and menstruation characteristics. Our goal was to examine whether high breast milk PBDE levels in reproductive-age females lead to interference with menstruation characteristics. We analyzed 15 PBDE congeners in 46 breast milk samples. Fifteen PBDE congeners (BDE-15, 28, 47, 49, 99, 100, 153, 154, 183, 196, 197, 203, 207, 208, and 209) were analyzed using a gas chromatograph equipped with a high resolution mass spectrometer. The mean sum of PBDEs (ΣPBDEs) in breast milk was 3.42 ng/g lipid. Women's age at menarche was not correlated with breast milk PBDE levels. Increased BDE-208 and 209 levels were significantly associated with the prolonged length of average and the longest menstrual cycle independent of age, pre-pregnant BMI, and parity. Higher concentrations of ΣPBDEs and the higher brominated PBDEs from BDE-183 to 209, except 197, were significantly linked to women whose menstruation periods were still coming irregularly at the sampling time. Age-adjusted odds ratios (ORs) of BDE-153, 183, 207, 208, and ΣPBDEs were significantly higher in women with length of average menstrual cycle > 32 days, compared to the control. Women whose menstruation periods still came irregularly when they were 18 years old had higher age-adjusted ORs of BDE-207, 208, 209, and ΣPBDEs than those whose periods came regularly at the same age. Although ΣPBDEs and certain higher brominated PBDEs appear to have potential to prolong length of average menstrual cycle and delay the age when menstruation periods begin coming regularly, these findings are not conclusive because our sample size is small and more scientific evidence is needed.

Prey Species as Possible Sources of PBDE Exposures for Peregrine Falcons (Falco peregrinus) Nesting in Major California Cities

Our earlier findings indicate that (1) peregrine falcons (Falco peregrinus anatum Bonaparte) nesting in major California cities have among the highest polybrominated diphenyl ether (PBDE) levels in the world (max ∑PBDEs=100 ppm), and (2) Big City peregrines have higher levels and proportions of the higher-brominated congeners (hepta- to deca-BDEs) than do their Coastal counterparts. In this study we classified the prey species (n =185) from the remains of prey (feathers) at 38 peregrine nest sites over 25 years (1974-1998). We grouped the prey species into 15 categories based on diet and found distinctly different prey patterns for Big City vs. Coastal peregrines. Big City peregrines had a higher (almost three times) weight percentage intake of food waste-eating birds (e.g., rock pigeons, Columba livia) than Coastal peregrines. These differing prey patterns suggest diet as a potential source of the unusually high levels and proportions of higher-brominated PBDEs in Big City peregrines. The relative contributions of diet and dust (e.g., preening) exposure to PBDE patterns in Big City peregrines will be explored in future investigations.

Brominated flame retardants in house dust from e-waste recycling and urban areas in South China: Implications on human exposure

Brominated flame retardants (BFRs) were examined in house dust from the electronic waste (e-waste) recycling and urban areas of South China. The concentrations of polybrominated diphenyl ethers (PBDEs) were in the range of 227–160,000 ng/g in the e-waste recycling area and 530–44,000 ng/g in the urban area. These values were much higher than other BFRs, except for novel decabromodiphenyl ethane (DBDPE) whose value of 100–47,000 ng/g was dominant in approximately 1/4 of the samples from the urban area. Urban dust PBDE levels were generally higher than those in many European and Asian countries and comparable to the values found in North America. Urban dust DBDPE levels were higher than those of other areas in the world. The distinct dust BFR profiles observed in the two studied areas were reflective of activities in these areas (electronics industry vs. e-waste recycling). The presence of BDE202, as well as the BDE197 to BDE201 and the nona-BDEs to deca-BDE ratios in the dust samples from the studied areas were probably indicative of environmental degradation of deca-BDE. The estimated daily intakes (EDIs) of average adult and toddler via house dust ranged from 37.0 to 304 ng/day for PBDEs and from 3.01 to 87.6 ng/day for all other BFRs in the studied areas. The EDIs via house dust were much higher than those via other indoor pathways (air, fish, human milk, and toys). Despite the potentially low deleterious risk of PBDE exposure via house dust as suggested by the hazard quotients, this exposure pathway should be of great concern because of the higher BFR exposures for children and the presence of other BFRs (such as DBDPE) which have not yet been fully investigated.

An Inkling of Suspicion: Prenatal Exposure to PBDEs and Neurodevelopmental Impairment

A longitudinal cohort study of more than 150 U.S. children conducted over 7 years associates prenatal exposure to higher concentrations of polybrominated diphenyl ether (PBDE) flame retardants with lower scores on tests of neurodevelopment [EHP 118:712–719; Herbstman et al.]. This is the second recent epidemiologic study to link PBDEs with evidence of adverse effects on brain development, although differences in methodology between this and the other study [EHP 117:1953–1958; Roze et al.] make direct comparisons difficult. PBDE flame retardants have been used for decades in a wide variety of goods, including automobile and airplane components, electronics, and home and office furnishings. The toxicologic evidence linking PBDEs to adverse health effects led the European Union to use the precautionary principle as the basis for banning all three PBDE formulations (penta, octa, and deca). In the United States, manufacturers voluntarily discontinued the penta and octa formulations in 2004 and have agreed to phase out deca by the end of 2012. The mothers of the children in the current study were pregnant at the time of the World Trade Center (WTC) attacks in 2001 and gave birth at a hospital within 2 miles of the WTC site. The women were recruited for a study on the effects of exposure to compounds in dust from the decimated towers. PBDEs were measured in the cord blood of 210 infants, and 152 of these children later participated in at least one round of neurodevelopmental testing conducted at 1, 2, 3, 4, and 6 years of age. The children with higher levels of exposures consistently had, on average, lower developmental scores at each time point compared with less-exposed children; the association was particularly evident at age 4 years. The researchers were not able to evaluate associations with developmental delay because few children had developmental scores low enough to meet the criterion for this outcome. However, in many cases average test scores in children with exposures in the highest 20% were 5–11 points lower than average scores for less-exposed children. Although some evidence suggests the PBDE exposure seen in the children could be related to the WTC attack, the authors say “it is certain” that sources other than the WTC contributed to the PBDE levels in the infants’ cord blood. Because the levels observed in these children were similar to those reported in other U.S. populations, the new research suggests the observed effects could be widespread. According to the authors, these findings are consistent with reports of hyperactivity and learning and memory deficits in experiments with mice exposed neonatally to PBDEs. Other work, most recently a laboratory study using human cells [EHP 118:572–578; Schreiber et al.], suggests PBDEs may interfere with thyroid hormones critical for normal brain development. The authors point out that additional studies exploring associations between PBDE exposure and developmental effects are under way. In the meantime, they say identifying opportunities to reduce people’s exposure to these compounds should be a priority.

Pregnant Pause: Does Maternal PBDE Exposure Extend Time to Pregnancy?

Vol. 118, No. 5 NewsOpen AccessPregnant Pause: Does Maternal PBDE Exposure Extend Time to Pregnancy? Julia R. Barrett Julia R. Barrett Search for more papers by this author Published:1 May 2010https://doi.org/10.1289/ehp.118-a217aCited by:1AboutSectionsPDF ToolsDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InRedditEmail Animal studies indicate polybrominated diphenyl ethers (PBDEs) are endocrine disruptors, potentially affecting the role of thyroid hormones in regulating the reproductive cycle and fertility. The compounds also have been associated with delayed puberty and altered estradiol levels in female animals. Very little is known about the potential effects of PBDEs on human reproductive health, though, and a new study is the first to characterize a specific concern—a relationship between PBDE blood concentrations and a delay in achieving pregnancy [EHP118:699–704; Harley et al.].PBDEs are used as flame retardants in furniture, carpeting, textiles, electronics, and plastics. Commercial mixtures of PBDEs contain a variety of congeners, or chemical variations. Data collected by the Centers for Disease Control and Prevention suggest 97% of Americans may have detectable levels of PBDEs in their blood.The current study included 223 pregnant women enrolled in the Center for the Health Assessment of Mothers and Children of Salinas (CHAMACOS), a longitudinal birth cohort study focused on environmental exposures and reproductive health in California’s Salinas Valley. Upon enrollment, the women reported their reproductive history, previous use of contraception and fertility medication, whether the pregnancy was planned, and how long it took to become pregnant after stopping contraception.Blood samples collected around 26 weeks of pregnancy were analyzed for 10 PBDE congeners. Statistical analyses focused on those most commonly found: BDE-47, BDE-99, BDE-100, and BDE-153. BDE-100 and BDE-153 were the most strongly associated with longer time to pregnancy. For each month, the likelihood of becoming pregnant was 40% or 50% lower with a 10-fold increase in concentration of BDE-100 or -153, respectively. With a 10-fold increase in the total of all 4 congeners, there was a 30% decrease in the odds of pregnancy each month.The study relied on self-reported time to pregnancy, which is subject to a number of biases. In addition, the study’s findings are limited to 4 PBDE congeners and may not extend to a broader population. Consequently, further research incorporating more congeners and a more representative population is needed. However, given the likelihood of PBDE exposure in the general population, even a small effect of these chemicals on fertility may affect a large number of individuals.FiguresReferencesRelatedDetailsCited By Gao Y, Chen L, Wang C, Zhou Y, Wang Y, Zhang Y, Hu Y, Ji L, Shi R, Cui C, Ding G, Jin J and Tian Y (2016) Exposure to polybrominated diphenyl ethers and female reproductive function: A study in the production area of Shandong, China, Science of The Total Environment, 10.1016/j.scitotenv.2016.07.181, 572, (9-15), Online publication date: 1-Dec-2016. Vol. 118, No. 5 May 2010Metrics About Article Metrics Publication History Originally published1 May 2010Published in print1 May 2010 Financial disclosuresPDF download License information EHP is an open-access journal published with support from the National Institute of Environmental Health Sciences, National Institutes of Health. All content is public domain unless otherwise noted. Note to readers with disabilities EHP strives to ensure that all journal content is accessible to all readers. However, some figures and Supplemental Material published in EHP articles may not conform to 508 standards due to the complexity of the information being presented. If you need assistance accessing journal content, please contact [email protected]. Our staff will work with you to assess and meet your accessibility needs within 3 working days.

Exposure of activated alveolar macrophages to brominated flame retardants augments the release of pro‐inflammatory cytokines in vitro

Several environmental pollutants have been shown to have adverse effects on immune function that may result in respiratory conditions. In addition to diet, inhalation of dust is a major route of exposure of polybrominated diphenyl ethers (PBDEs) however; the impact of PBDEs on the immune response is unclear. The objective of this in vitro study was to determine the impact of physiological levels of PBDEs on the release of the pro‐inflammatory cytokine, TNFα, by activated alveolar macrophages. Porcine alveolar macrophages were seeded in three 24‐well plates in RPMI growth media supplemented with 10% porcine serum and incubated for 24‐hours (5% CO2, 37°C). After 24‐hours, the cells were activated by inoculation with PMA (0.01 mg/ml) and ionomycin (0.05 mg/ml) in 1% DMSO. In addition to the activating stimulus, three different concentrations of the PBDE mixture DE‐71 in MeOH were introduced to the wells (500 ng/mL DE‐71, 0.02% MeOH; 1000 ng/mL DE‐71, 0.04% MeOH; 2000 ng/mL DE‐71, 0.08% MeOH) (n = 9 per treatment). After 6‐hour incubation, conditioned media was removed, centrifuged, and stored at −80°C until analysis of TNFα via ELISA. Compared to controls, cells exposed to PMA and 1000 and 2000 ng/mL of PBDEs released 33 and 28% more TNFα, respectively (p < 0.05). As increased TNFα may indicate an increase in inflammation, findings suggest that chronic exposure to airborne PBDEs may be a cause of chronic respiratory inflammation.UNH Experimental Station Project H495.Grant Funding Source: UNH Experimental Station Project H495

Brain Drain? PBDEs Alter Development of Human Brain Cells

Vol. 118, No. 4 NewsOpen AccessBrain Drain? PBDEs Alter Development of Human Brain Cells Kellyn S. Betts Kellyn S. Betts Search for more papers by this author Published:1 April 2010https://doi.org/10.1289/ehp.118-a173aCited by:1AboutSectionsPDF ToolsDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InReddit A new laboratory study demonstrating that polybrominated diphenyl ethers (PBDEs) can alter human fetal brain cells may explain at least in part the neurotoxicity recently documented in epidemiologic studies of young children exposed to PBDEs and previously shown in animal models [EHP118:572–578; Schreiber et al.]. The new study, the first to examine PBDE neurotoxicity in a human cell–based system, links the brain cell alterations to endocrine disruption.A wealth of data demonstrates that babies can be exposed to significant amounts of PBDE flame retardants both in the womb and through breastfeeding. Although all 3 PBDE formulations—penta, octa, and deca—are banned in Europe, and the penta and octa formulations were discontinued in the United States (deca also is banned in some states), PBDEs may still be used in some new U.S. products and in wares manufactured elsewhere. They also are found in a wide variety of older plastic consumer goods that remain in use in many homes, businesses, and automobiles. The PBDEs are known to migrate into indoor dust, posing a particularly high exposure risk to infants and toddlers because of their characteristic hand-to-mouth behavior.To investigate how PBDEs may impact the developing fetal brain, the team of scientists employed a method for evaluating human developmental neurotoxicity they had recently developed [EHP 117:1131–1138] as an alternative to animal testing. This method uses primary fetal human neural progenitor cells (hNPCs) cultured to produce complex 3-dimensional cellular systems called neurospheres. Neurospheres undergo the same basic processes that occur during the early stages of normal human brain development: cell proliferation, differentiation, and migration. Tests conducted with neurospheres may help identify exogenous substances that disturb these basic processes in vivo.The researchers focused on 2 of the PBDE compounds that accumulate the most in humans, BDE-47 and BDE-99. At concentrations below levels that cause cell death, they found these compounds could reduce the migration of the hNPCs—which suggests the possibility of adverse effects on brain development—and the effects increased with higher PBDE concentrations. At the highest tested concentration (10 μM), BDE-47 decreased the distance the cells migrated by more than 25% compared with unexposed cells, whereas the same concentration of BDE-99 decreased the distance by more than 30%. Additional testing established that both compounds also interfered with the differentiation of immature progenitor cells into neurons and oligodendrocytes.Further tests suggested the PBDE compounds affected cell migration and differentiation by interfering with thyroid hormone signaling, an endocrine-disrupting effect that could be associated with additional impacts throughout a person’s life. Followup work to determine whether PBDEs cause the same effects in rodent neurospheres would facilitate extrapolation from animals to humans, the authors say.Other work has shown the tendency of PBDEs to accumulate in brain and neuronal cells, and the researchers used radiolabeled BDE-47 to measure an accumulation in test cells of approximately 60-fold. Considered with available human exposure data, these data suggest current PBDE exposure levels are likely to be of concern for human health, the authors write. Two recent studies have linked PBDEs with subtle changes in childrens’ IQs and behavior [EHP 117:1953–1958 and EHP doi:10.1289/ehp.0901340], and the authors say additional studies are needed to assess these associations.This fluorescence micrograph of differentiated neural progenitor cells shows neurons in green, glial cells in red, and cell nuclei in deep blue (the turquoise results from the overlay of the blue and green channels).FiguresReferencesRelatedDetailsCited by Akbar M, Narayanan S, Restaino M and Agah M (2014) A purge and trap integrated microGC platform for chemical identification in aqueous samples, The Analyst, 10.1039/C4AN00254G, 139:13, (3384-3392) Vol. 118, No. 4 April 2010Metrics About Article Metrics Publication History Originally published1 April 2010Published in print1 April 2010 Financial disclosuresPDF download License information EHP is an open-access journal published with support from the National Institute of Environmental Health Sciences, National Institutes of Health. All content is public domain unless otherwise noted. Note to readers with disabilities EHP strives to ensure that all journal content is accessible to all readers. However, some figures and Supplemental Material published in EHP articles may not conform to 508 standards due to the complexity of the information being presented. If you need assistance accessing journal content, please contact [email protected]. Our staff will work with you to assess and meet your accessibility needs within 3 working days.

Cytotoxicity and apoptosis induction on RTG-2 cells of 2,2′,4,4′-tetrabromodiphenyl ether (BDE-47) and decabrominated diphenyl ether (BDE-209)

Recently, the environmental residues of polybrominated diphenyl ethers (PBDEs) have markedly increased. In particular, the levels of certain PBDE congeners in fish have raised concern regarding potential risks associated with dietary PBDEs exposures. However, little is known regarding PBDE-mediated cell injury in relevant in vitro fish cell models. In this study, the cytotoxic effects of 2,2′,4,4′-tetrabromodiphenyl ether (BDE-47) and decabrominated diphenyl ether (BDE-209) on RTG-2 cells were investigated. RTG-2 cells were incubated with different concentrations of BDE-47 and BDE-209 (1–100μM) for 72h, and a set of bioassays were conducted to measure: cell viability (evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay and neutral red (NR) uptake), lactate dehydrogenase (LDH) leakage, reactive oxygen species (ROS) formation and cell apoptosis. The results showed that BDE-47 and BDE-209 inhibited the cells viability, increased LDH leakage, and induced cell apoptosis in time and concentration-dependent manner. All significant effects were observed at concentrations of 12.5μM and above for BDE-47 and 25μM and above for BDE-209 (P<0.05). At the concentration of 100μM BDE-47 and BDE-209, the cell viability of the exposed cells dropped to about 40% and 50% of the control, and the apoptotic rates were 52.6% and 34.6%, respectively. After 12h exposure, a concentration-dependent increases of BDE-47 and BDE-209 (12.5–100μM) in ROS formation were observed. Collectively, the results of cell viability, LDH leakage, cell apoptosis and ROS formation demonstrated that the toxic mechanism of PBDEs on RTG-2 might be mediated by oxidative stress.

PBDE Concentrations in Women’s Serum and Fecundability

BackgroundExposure to polybrominated diphenyl ether (PBDE) flame retardants is widespread, with 97% of Americans having detectable levels. Although PBDEs have been associated with reproductive and hormonal effects in animals, no human studies have examined their association with fertility.ObjectivesThis study was designed to determine whether maternal concentrations of PBDEs in serum collected during pregnancy are associated with time to pregnancy and menstrual cycle characteristics.MethodsPregnant women (n = 223) living in a low-income, predominantly Mexican-immigrant community in California were interviewed to determine how many months they took to become pregnant. Blood samples were collected and analyzed for PBDEs. PBDE concentrations were lipid adjusted and log10 transformed. Analyses were limited to PBDE congeners detected in > 75% of the population (BDEs 47, 99, 100, 153). Cox proportional hazards models modified for discrete time were used to obtain fecundability odds ratios (fORs) for the association of PBDEs and time to pregnancy.ResultsWe detected all four congeners in > 97% of women. Increasing levels of BDEs 47, 99, 100, 153 and the sum of these four congeners were all associated with longer time to pregnancy. We observed significantly reduced fORs for BDE-100 [adjusted fOR = 0.6; 95% confidence interval (CI), 0.4–0.9], BDE-153 (adjusted fOR = 0.5; 95% CI, 0.3–0.8), and the sum of the four congeners (adjusted fOR = 0.7; 95% CI, 0.5–1.0). PBDEs were not associated with menstrual cycle characteristics.ConclusionsWe found significant decreases in fecundability associated with PBDE exposure in women. Future studies are needed to replicate and confirm this finding.

Spatial distribution of hexabromocyclododecanes (HBCDs), polybrominated diphenyl ethers (PBDEs) and organochlorines in bivalves from Japanese coastal waters

In order to elucidate the spatial distribution of brominated flame retardants (BFRs) in the Japanese coastal environment, hexabromocyclododecanes (HBCDs), polybrominated diphenyl ethers (PBDEs) and organochlorines (OCs: PCBs, DDTs, CHLs, HCHs, HCB) were determined in bivalves (oysters and mussels) collected from Japanese coastal waters. HBCDs and PBDEs were detected in all samples analyzed. Concentration ranges of HBCDs were 12–5200 ng g −1 lipid wt., followed by PCBs (20–3100 ng g −1) > PBDEs (3.1–86 ng g −1 lipid wt.). The highest concentration of HBCDs was found in the Osaka region. This result indicates that HBCDs are ubiquitous and predominant compounds in bivalves from the Japanese coastal waters. Since no species differences between oysters and mussels were observed for the bioaccumulation properties of HBCDs and PBDEs, oysters could be utilized for BFR contamination monitoring worldwide as an alternative to mussels. Global comparisons between oysters and mussels showed that HBCD concentrations in Japan are among the highest levels reported from Asia and Europe. Estimated dietary exposures of HBCDs and PBDEs through seafood were 0.45–34 ng kg body weight −1 d −1, and 0.054–6.8 ng kg body weight −1 d −1, respectively. These exposure levels were more than 1000 times lower than the lowest observable effects or no observable adverse effects levels for HBCDs and PBDEs, respectively.

Prenatal Exposure to PBDEs and Neurodevelopment

BackgroundPolybrominated diphenyl ethers (PBDEs) are widely used flame retardant compounds that are persistent and bioaccumulative and therefore have become ubiquitous environment contaminants. Animal studies suggest that prenatal PBDE exposure may result in adverse neurodevelopmental effects.ObjectiveIn a longitudinal cohort initiated after 11 September 2001, including 329 mothers who delivered in one of three hospitals in lower Manhattan, New York, we examined prenatal PBDE exposure and neurodevelopment when their children were 12–48 and 72 months of age.MethodsWe analyzed 210 cord blood specimens for selected PBDE congeners and assessed neurodevelopmental effects in the children at 12–48 and 72 months of age; 118, 117, 114, 104, and 96 children with available cord PBDE measurements were assessed at 12, 24, 36, 48, and 72 months, respectively. We used multivariate regression analyses to evaluate the associations between concentrations of individual PBDE congeners and neurodevelopmental indices.ResultsMedian cord blood concentrations of PBDE congeners 47, 99, and 100 were 11.2, 3.2, and 1.4 ng/g lipid, respectively. After adjustment for potential confounders, children with higher concentrations of BDEs 47, 99, or 100 scored lower on tests of mental and physical development at 12–48 and 72 months. Associations were significant for 12-month Psychomotor Development Index (BDE-47), 24-month Mental Development Index (MDI) (BDE-47, 99, and 100), 36-month MDI (BDE-100), 48-month full-scale and verbal IQ (BDE-47, 99, and 100) and performance IQ (BDE-100), and 72-month performance IQ (BDE-100).ConclusionsThis epidemiologic study demonstrates neurodevelopmental effects in relation to cord blood PBDE concentrations. Confirmation is needed in other longitudinal studies.

The Automobiles as Indoors.

In this review we aimed to attract attention to toxic chemicals in cars and their effect on health. People spend most of their times in indoors such as houses, workplaces, malls, sport centers, train, transportation vehicles (train, plane, cars). In US, citizens spend nearly 100 minutes in cars per day. There are safety problems in cars except than seatbelt and airbag. Some of these are seats, furnishing, cushions for arm and head, floor covering, accessories and plastic parts. In a study conducted in Japan, more than 160 volatile organic compounds (VOC) had been determined in new cars and a three years old car. Some of the pollutants are formaldehyde, toluen, xylene, ethylbenzene and styrene. Also Polybrominated diphenyl ethers (PBDEs), which may be degradated by sunshine in hot seasons are measured within the outomobiles. There is a big gap of studies about the pollutants in cars and researches have to be conducted. Manufacturers should use nonhazardous material or less toxic chemicals to reduce exposure of VOCs, PBDEs and phthalates. Drivers can reduce the these chemicals by using solar reflectors and avoiding to park under sunlight.

Chronic, dietary polybrominated diphenyl ether exposure affects survival, growth, and development of Rana pipiens tadpoles

Levels of polybrominated diphenyl ethers (PBDEs) in the environment have been increasing rapidly over the past two decades; however, the toxicology of these compounds to aquatic organisms is poorly understood. Because amphibians play a role in both aquatic and terrestrial food webs, and are currently undergoing worldwide population declines, it is of interest to determine how PBDEs may affect amphibian health. This is the first study that reports chronic, dietary effects of environmentally relevant levels (7-277 ng/g wet food) of PBDEs in amphibians throughout larval development. Beginning at the free-swimming stage (Gosner Stage [GS] 25), Rana pipiens tadpoles were orally exposed to a technical pentabromodiphenyl ether mixture (DE-71) through metamorphic climax (GS 42). On exposure day 43, a subset of tadpoles was removed for body residue analysis. Sum PBDEs in whole-body tissue correlated linearly to dietary concentrations with BDE-99 represented as the highest contributing congener in both diet and tissue. Survival among all treatments compared to the control was decreased by DE-71 exposure. Further, growth and development were delayed in all but the highest treatment, perhaps indicating greater PBDE tolerance among those individuals that survived the highest treatment. Time to metamorphic climax was delayed, on average, 22 to 36 d in DE-71-treated tadpoles compared to control tadpoles. Additionally, size at metamorphosis was smaller in the highest treatment, suggesting that individuals that survived and metamorphosed similarly to the controls did so with a trade-off in size. At environmentally relevant levels, PBDEs induced mortality as well as sublethal effects on developing tadpoles through dietary exposure.

Polybrominated Diphenyl Ethers in Umbilical Cord Blood and Relevant Factors in Neonates from Guiyu, China

We aimed to evaluate the exposure of neonates to polybrominated diphenyl ethers (PBDEs) from a primitive e-waste (obsolete electrical and electronic devices) recycling area, in Guiyu, China, and a control area, Chaonan, China, through umbilical cord blood (UCB), the health effects, and relevant factors. Questionnaires were addressed, and UCB was collected shortly after birth from 153 pregnant women between May and July 2007. Blood samples were prepared by liquid-liquid extracting methods. PBDE concentration was determined by gas chromatography/mass spectrometry in the electron capture negative ionization mode. The total PBDE concentration was higher in UCB samples from Guiyu than in Chaonan samples (median 13.84, range 1.14-504.97 ng g(-1) lipid, vs 5.23, range 0.29-363.70 ng g(-1) lipid) (p < 0.05). BDE-209 was the dominant PBDE congener, followed by BDE-47, -153, and -99. Residence in Guiyu, which is a site for e-waste recycling, involvement in e-waste recycling, and the residence also being used as a family workshop were significant factors contributing to PBDE exposure. PBDE levels significantly differed in neonates by normal birth and adverse birth outcomes including stillbirth, low birth weight, and premature delivery (p < 0.05). The neonates from Guiyu are exposed to high levels of PBDEs. Prenatal exposure to PBDEs may affect neonates' health in Guiyu, which still needs to be evaluated in larger epidemiological studies.

Species-specific accumulation of polybrominated diphenyl ether flame retardants in birds of prey from the Chesapeake Bay region, USA

Compared to organochlorines, little is known about polybrominated diphenyl ether (PBDE) contamination of birds of prey breeding in the Chesapeake Bay, the largest estuary in the U.S. This study examined and compared PBDE contamination in eggs of osprey, double-crested cormorant, brown pelican and peregrine falcon from this area. Several legacy persistent organic pollutants such as PCBs and DDE were also investigated. The level of urbanization of the landscape appeared to influence the level of PBDE exposure. PBDE congener distribution patterns varied between piscivorous and terrestrial-feeding birds. This suggests individual congeners may be subject to differences in bioaccumulation, biomagnification or metabolism in the aquatic and terrestrial food webs. Biomagnification of PBDEs was studied in the Bay aquatic food chains for the first time. A biomagnification factor of 25.1 was estimated for ΣPBDEs for the fish – osprey egg food chain. Hazard quotients, applied as a preliminary evaluation, indicated that PBDEs may pose a moderate hazard to ospreys and peregrine falcons through impairment of reproductive performance.

Maternal PBDE Exposure and Time to Pregnancy

ISEE-0865 Objective: To examine the association of maternal exposure to polybrominated diphenyl ethers (PBDEs) with time to pregnancy (TTP). Methods: The study population comprised 225 pregnant women participating in the Center for the Health Assessment of Mothers and Children of Salinas (CHAMACOS) study, a cohort study of low-income, predominantly Mexican women living in an agricultural region of California. Concentrations of 10 PBDE congeners were measured in serum collected from the women near the end of the second trimester of pregnancy using gas chromatography and isotope dilution high resolution mass spectrometry. Analyses were limited to four PBDE congeners (BDE-47, −99, −100 and −153) that were detected in more than 75% of women. TTP was defined as the number of months it took to become pregnant, censored at 13 months. Women who were using contraceptives at the time of conception (i.e. contraceptive failures) were excluded. We analyzed the association of TTP with lipid-adjusted PBDEs as continuous variables using discrete-time Cox proportional hazards models, to obtain fecundability odds ratios (fOR). PBDE levels were log transformed and levels below the limit of detection (LOD) were given the values of the LOD/2. All analyzes were adjusted for covariates. Results: Median TTP was 3 months (range: 0–180 months). All four PBDE congeners were associated with longer time to pregnancy (i.e. fOR < 1). Each 10-fold increase in BDE-153 was associated with a 50% decreased odds of conceiving each month (adjusted fOR = 0.5, P = 0.001). Similar results were seen for BDE-47 (adjusted fOR = 0.7, P = 0.05), −99 (adjusted fOR = 0.7, P = 0.08), and −100 (adjusted fOR = 0.6, P = 0.006). Conclusions: Higher maternal PBDE levels during pregnancy were associated with longer time to pregnancy in this population.