Association between fetal growth restriction and maternal exposure to polybrominated diphenyl ethers.

Humans are exposed to polybrominated diphenyl ethers (PBDEs) via ingestion of food, dust inhalation, and dermal absorption. Exposure to PBDEs via the placenta and breast milk is a special and important pathway in infants. This nested case-control study aimed to investigate the levels of PBDEs in maternal serum and colostrum, and to assess the association between the occurrence of fetal growth restriction (FGR) and prenatal exposure to PBDEs. We recruited 293 mother-newborn pairs, including 98 FGR cases and 195 healthy controls in Wenzhou, China. Maternal serum and colostrum samples were collected during pregnancy and after delivery, respectively, and the levels of PBDEs were measured by gas chromatography-tandem mass spectrometry. The total levels of PBDEs in maternal serum and colostrum were found to be in equilibrium, but congener profiles of PBDEs in these matrices were different. Increased BDE-207, BDE-209, ∑BDE196-209 and ∑PBDEs levels in maternal serum and BDE-99, ∑BDE17-154 and ∑PBDEs levels in colostrum were correlated with decreased birth weight Z score. Increased concentrations of higher brominated BDEs in maternal serum (odds ratio (OR) = 1.010, 95%CI = 1.003-1.018) and low-to moderately brominated BDEs in colostrum (OR = 1.004, 95%CI = 1.000-1.009) were associated with increased risk of FGR, which showed an exposure-response relationship. In addition, infants with FGR were more exposed to PBDEs in colostrum after birth than healthy infants. Longitudinal birth cohort studies are needed to determine the prolonged effect of PBDEs exposure on the growth of FGR infants in the future.

Prenatal exposure to legacy contaminants and visual acuity in Canadian infants: a maternal-infant research on environmental chemicals study (MIREC-ID).

BACKGROUND: Prenatal exposure to environmental contaminants can have deleterious effects on child development. While psychomotor, cognitive and behavioural outcomes have been investigated in relation to chronic exposure, the associations with visual functions remains unclear. The present study's aim was to assess the associations of prenatal exposure to legacy persistent organic pollutants and heavy metals with visual acuity in Canadian infants. The potential protective effects of selenium against mercury toxicity were also examined. METHODS: Participants (mean corrected age = 6.6 months) were part of the Maternal-Infant Research on Environmental Chemicals (MIREC) study. Concentrations of polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), lead and mercury were measured in maternal blood during pregnancy, as well as in the cord blood. The Teller acuity card test (TAC) (n = 429) and the visual evoked potentials in a sub-group (n = 63) were used to estimate behavioural and electrophysiological visual acuity, respectively. Multivariable linear regression models were used to investigate the relationship between exposure to each contaminant and visual acuity measures, while controlling for potential confounders. Breastmilk selenium, which was available for about half of the TAC and VEP samples, was also taken into account in the mercury models as exploratory analyses. RESULTS: We observed no significant associations between exposure to any contaminants and TAC. Analyses revealed a negative trend (p values < 0.1) between cord blood lead and mercury and electrophysiological visual acuity, whereas PCB and PBDE showed no association. When adding breastmilk selenium concentration to the mercury models, this association became statistically significant for cord concentrations (ß = - 3.41, 95% CI = - 5.96,-0.86), but also for blood levels at 1st and 3rd trimesters of pregnancy (ß = - 3.29, 95% CI = - 5.69,-0.88). However, further regression models suggested that this change in estimates might not be due to adjustment for selenium, but instead to a change in the study sample. CONCLUSIONS: Our results suggest that subtle, but detectable alterations of infant electrophysiological visual acuity can be identified in a population prenatally exposed to low mercury concentrations. Compared to behavioural visual acuity testing, electrophysiological assessment may more sensitive in detecting visual neurotoxicity in relation with prenatal exposure to mercury.

Vitamin C intervention may lower the levels of persistent organic pollutants in blood of healthy women - A pilot study.

Emerging evidence suggests that exposure to endocrine-disrupting chemicals including persistent organic pollutants (POPs) such as organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), and polybrominated diphenyl ethers (PBDEs) has a long term impact on human health. The goal of this pilot study was to test whether antioxidant intervention by vitamin C supplementation may be a remedial approach to decrease body burden of POPs in humans. Using solid phase extraction coupled with a triple quadrupole mass spectrometer and a gas chromatography high resolution mass spectrometry, we measured 18 PCBs, 7 OCPs, and 5 PBDEs in the blood of 15 healthy California women (8 were obese/overweight and 7 had normal weight) before and after 2 months of vitamin C supplementation (1000 mg/day). We observed higher PBDE levels than PCBs and OCPs, but only PCB and OCP levels were strongly and positively correlated with participant's BMI and age. We also found statistically significant decreases in 6 PCBs (PCB-74, PCB-118, PCB-138, PCB-153, PCB-180, and PCB-187), and 2 OCPs (4,4'-DDE, and 4,4'-DDT), but not PBDEs after vitamin C supplementation. Pending confirmation of this pilot finding in a larger study of both sexes, vitamin C intervention may have important public health implications in protecting health by reducing body burdens of POPs.

Polybrominated diphenyl ethers in maternal serum, umbilical cord serum, colostrum and mature breast milk. Insights from a pilot study and the literature.

Human serum and mother's milk are frequently used to assess exposure to polybrominated diphenyl ethers (PBDEs), including transplacental transfer to the foetus. However, little is known about the kinetics of PBDEs, especially the highly brominated BDE congeners. In this pilot study, maternal serum samples were collected from 10 women at delivery and five to six weeks post partum. Umbilical serum was also obtained. Milk was donated two to five days, and five to six weeks after delivery. The amount of PBDEs in these samples was determined using liquid-liquid extraction and GC/MS. Low, moderately and highly brominated diphenyl ethers were present in umbilical cord serum, indicating placental transfer. The lipid-adjusted levels of BDE-47, BDE-207 and BDE-209 were similar in maternal and umbilical cord serum, whereas the cord serum levels for the penta- to octa-BDEs quantified were lower than in maternal serum. Marked changes were seen in the congener pattern in breast milk during the first month of lactation, whereas maternal serum levels did not change significantly. The general pattern was an enrichment of low to moderately brominated congeners (i.e. from BDE-17 to BDE-154, with the exception of BDE-28) in colostrum compared with maternal serum. In contrast, more highly brominated congeners were found at similar, or lower levels in colostrum than in maternal serum. After the transition from colostrum to mature milk, the levels of BDE-153 and BDE-209 were substantially reduced, and BDE-209 was below the limit of detection in 6 out of 9 samples. A literature review on the design and reporting of studies on the transfer of PBDEs from mother to infant revealed a lack of transparency in many cases. The use of the recently published STROBE-ME guidelines is therefore recommended.

Effects of dose, administration route, and/or vehicle on decabromodiphenyl ether concentrations in plasma of maternal, fetal, and neonatal rats and in milk of maternal rats.

The effects of route and vehicle on blood and milk levels of decabromodiphenyl ether (DecaBDE; CASRN 1163-19-5) were investigated in the rat to assist in the design and conduct of a developmental neurotoxicity study. Blood plasma and/or milk concentrations were determined in dams, fetuses, and/or nursing pups after repeated DecaBDE administration by gavage throughout gestation or gestation and lactation using corn oil (CO) or soyaphospholipon/Lutrol F 127-water (SPL) as the vehicle. The impact of vehicle on plasma levels was also investigated in pups derived from naive dams after a single postnatal dose. This study reports for the first time fetal and neonatal plasma concentrations concurrent with those of maternal plasma and/or milk. Higher concentrations of DecaBDE were achieved in plasma and in milk with CO than with SPL. Furthermore, pups derived from dams treated with only SPL were lower in body weight, compared with those from dams treated with either CO, CO and DecaBDE, or SPL and DecaBDE. The study further shows that exposure to DecaBDE is relatively consistent across the dose range of 100 to 1000 mg/(kg · day) when administered in CO.