The World Health Organization estimates that environmental factors are responsible for approx. 13% of the disease burden in Canada. Two major concerns are flame retardants and phthalates, which are used in many household items (foam furniture, appliances, cosmetics, plastics) and are released into the air, water and food we consume on a daily basis. For the past 40 years, Canadians have been exposed to these contaminants, beginning during early fetal stages. Recent evidence suggests that these environmental chemicals may have harmful effects on our reproductive health.
This panel discussion from McGill University is a Café Scientifique.
Date: May 12, 2015
"What is infertility and how can science help us solve this problem?"
On May 7th 2013, Drs. Bernard Robaire and Patricia Monnier joined Dr. Hugh Clarke, Research Director of the Department of Obstetrics and Gynecology at the RI-MUHC and moderator Dominique Forget for a CIHR-funded Café Scientifique in Montreal. They discussed topics under the theme "Fertility: concerns, breakthroughts, horizons," which included the potential role of environmental contaminants, such as brominated flame retardants. Please see the source for video of the Café Scientifique:
Source (includes videos)
Published online: June 18, 2013
Journal Article: Organochlorine Pollutants and Female Fertility: A Systematic Review Focusing on In Vitro Fertilization Studies
"The possible adverse effects of organochlorine pollutants (OPs) on human fertility are a matter of concern. Direct evaluation of the effects on female fertility was made possible by the advent of in vitro fertilization (IVF). We conducted a systematic review to assess possible associations between OP levels and selected indicators of female fertility in the context of IVF. After harmonization, OP concentrations per unit of lipid varied considerably, OP concentrations were higher in follicular than in serum and conflicting results were obtained. No significant adverse association between OP concentration and female fertility was observed in some studies. In other reports, there were indications of various degrees of significance that oocyte, embryo quality, and implantation may have been impaired. Thus, this review provides no evidence to support the hypothesis that OPs impair female fertility but insufficient evidence to reject this hypothesis. Our conclusions are limited by the diversity of the protocols used, OPs studied, and the quality of the studies selected. The IVF provides a unique context in which to assess the impact of OPs on female fertility, but it is subject to several limitations. Potential frameworks for future studies are proposed."
Kadhel P, Monnier P, Boucoiran I, Chaillet N, Fraser WD (2012) Organochlodrine Pollutants and Female Fertility: A Systematic Review FOcusing on In Vitro Fertilization Studies. Reproductive Sciences 19, 1246-1259. doi:10.1177/1933719112446077
Online Publication Date: May 16, 2012
"As a reminder of just how persistent some toxic chemicals can be, a Johns Hopkins-led research team reports finding traces of long-banned DDT and PCBs along with other contaminants in the blood of 50 pregnant women checked from Baltimore and its suburbs..."
Read more/Source: The Baltimore Sun
Publication date: June 12, 2013
(Journal Article) Prenatal exposure to polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) may influence birth weight among infants in a Swedish cohort with background exposure: a cross-sectional study
"Background: Prenatal exposure to persistent organic pollutants, e.g. polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) has been suggested to negatively affect birth weight although epidemiological evidence is still inconclusive. We investigated if prenatal exposure to PCBs and PBDEs is related to birth weight in a Swedish population with background exposure.
Methods: Breast milk was sampled during the third week after delivery from first-time mothers in Uppsala county, Sweden 1996–2010 (POPUP cohort) (N = 413). Samples were analysed for di-ortho PCBs (CB-138, 153, 180) and tetra- to hexa- brominated PBDEs (BDE-47, 99, 100, 153). Simple and multiple linear regression models were used to investigate associations between lipid-adjusted, ln-transformed PCB and PBDE concentrations, and birth weight. Covariates included in the multivariate regression model were PCB and PBDE exposure, maternal age, pre-pregnancy BMI, weight gain during pregnancy, education, smoking, gender of the infant and gestational length. The effect of including fish consumption was also investigated.
Results: In the multivariate model, prenatal exposure to di-ortho PCBs was significantly associated with increased birth weight (β = 137; p = 0.02). The result did not change when gestational length was added to the model. An inverse association between PBDE(4) (sum of BDE-47, -99, -100 and −153) and birth weight was observed in the multivariate model including gestational length (β = −106; p = 0.04). Maternal pre-pregnancy BMI and weight gain during pregnancy were important confounders of the association between di-ortho PCBs and birth weight. The associations were not alleviated after adjustment for fish consumption, a major source of PCB and PBDE exposure. The observed associations were stronger for boys than for girls.
Conclusions: Our results indicate that prenatal exposure to di-ortho PCBs and PBDE(4) may influence birth weight in different directions, i.e. PCB exposure was associated with higher birth weight and PBDE exposure with lower birth weight. Maternal pre-pregnancy BMI and weight gain during pregnancy were important confounders that may hide positive association between di-ortho PCB exposure and birth weight if they are not included in the statistical model. We speculate that even small PCB- and PBDE-induced shifts in the distribution of birth weight may influence future public health in populations with background exposure."
Source: Lignell S, Aune M, Darnerud PO, Hanberg A, Larsson SC, Glynn A. 2013. Prenatal exposure to polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) may influence birth weight among infants in a Swedish cohort with background exposure: a cross-sectional study. Environ Health. 2013; 12: 44. doi: 10.1186/1476-069X-12-44
Publication date: May 31, 2013
(Journal Article) Parameters affecting the occurrence and removal of polybrominated diphenyl ethers in twenty Canadian wastewater treatment plants.
"This study determined PBDE levels in influent, primary effluent, and final effluent collected from diverse treatment processes including four aerated lagoons, two facultative lagoons, four primary treatments, eight secondary biological treatments and two advanced treatments. Parameters examined for correlation included seasonal temperature, community sizes, industrial inputs, and operational conditions. PBDE levels in influent were 21-1000 ng/L (median 190 ng/L). Higher concentrations in influent samples were found during summer, and in WWTPs which treated leachate and higher proportions of industrial wastewater vs. residential wastewater. Final effluent levels ranged between 3 and 270 ng/L (median 12 ng/L). Among all congeners, the sum of BDE-209, -47 and -99 accounted for 79 and 71% of total PBDEs in influent and final effluent, respectively, with BDE-209 having the highest proportion. Median removal efficiencies for all process types exceeded 90% except primary treatment at 70%. PBDE levels and removals were correlated to the levels and removals of conventional parameters that represent wastewater strength, such as chemical oxygen demand and total suspended solids. The role of the primary clarifier was significant (∼82% removal) and removal was associated with hydraulic retention time (HRT) and surface loading rate. Best removal of PBDEs was achieved at greater than 2000 mg/L mixed liquor suspended solids (MLSS), longer than 10 h of HRT, and 9 days of solids retention time."
Source: Kim M, Guerra P, Theocharides M, Barclay K, Smyth SA, Alaee M. 2013. Parameters affecting the occurrence and removal of polybrominated diphenyl ethers in twenty Canadian wastewater treatment plants. Water Res. 2013 May 1;47(7):2213-21. doi: 10.1016/j.watres.2013.01.031.
Emerging Priorities Division, Science and Risk Assessment Directorate, Science and Technology Branch, Environment Canada, Burlington, Canada.
Publication date: May 1, 2013
(Journal Article) Predictors of serum concentrations of polybrominated flame retardants among healthy pregnant women in an urban environment: a cross-sectional study.
"BACKGROUND: Polybrominated diphenyl ethers (PBDEs) are a class of brominated flame retardants commonly used in a wide range of products. Prenatal exposure to PBDEs has been associated with adverse neurodevelopment. Our objective was to characterize predictors of exposure to PBDEs among a multi-ethnic, low-income cohort of pregnant women enrolled from highly urban communities in New York City between years 2009-2010.
METHODS: During the first half of pregnancy we collected 316 maternal serum samples and administered an extensive questionnaire including items on demographics, diet and lifestyle. We measured 12 PBDE congeners in blood samples. Using bivariate and multivariate approaches, we regressed the most commonly detected PBDE congeners (PBDE-47, -99, -100 and -153) against potential demographic, dietary and lifestyle predictor variables.
RESULTS: At least one PBDE congener was detected in each serum sample. Our analyses demonstrate unique predictor patterns for PBDE-47, -99, -100 and -153 based on demographic, lifestyle and dietary characteristics of women. Higher education and increased use of household electronics were associated with higher levels of all 4 congeners. Six characteristics were associated with PBDE-153 serum concentrations, more than for any other congener. These include maternal education, household income, body mass index, solid dairy consumption, processed meat consumption and frequent use of household electronics.
CONCLUSIONS: PBDE exposure in this widespread in this cohort, though levels are lower than previous assessments of US pregnant women. Lower levels may be in response to legislation restricting the production, sale and use of these compounds. In our cohort, we did not observe any individual predictor or a consistent pattern of several predictors representing a significant source of PBDE exposure. These data suggest that legislation and policy may be more effective at reducing exposure than personal lifestyle modifications."
Source: Horton MK, Bousleiman S, Jones R, Sjodin A, Liu X, Whyatt R, Wapner R, Factor-Litvak P. 2013. Predictors of serum concentrations of polybrominated flame retardants among healthy pregnant women in an urban environment: a cross-sectional study. Environ Health. 2013 Mar 8;12(1):23. doi: 10.1186/1476-069X-12-23.
Department of Epidemiology, Mailman School of Public Health, Columbia University, New York, NY, USA
Publication date: March 8, 2013
The Royal College of Obstetricians and Gynaecologists has issued a paper looking at the "potential but unproven" risks from exposure to environmental chemicals in pregnancy. It says the purpose is to raise awareness and not to scare women.
Source: BBC News
Online Publication Date: June 04, 2013
Bellingham M, Sharpe RM (2013) Chemical Exposures During Pregnancy: Dealing with Potential, but Unproven, Risks to Child Health. RCOG Scientific Impact Paper No. 37.
"Flame retardants in first breast milk may have a small effect on mental development of toddlers, reports a new study from Spain. In tests measuring the toddlers' cognitive and motor skills, scores dropped 2 points for each 10-fold increase in total PBDEs in their mothers' milk. The flame retardants were widely used in furniture until 2005, and the last remaining PBDE will be phased out this year. Despite the bans, exposures are expected to continue for many years because of the high volume of the chemicals already in furniture cushions and electronics..."
Source: Environmental Health News
Publication date: May 9, 2013
Source: : Gascon, M, M Fort, D Martínez, A-E Carsin, J Forns,JO Grimalt, L Santa Marina, N Lertxundi, J Sunyer and M Vrijheid. 2012.Polybrominated diphenyl ethers (PBDEs) in breast milk and neuropsychological development in infants. Environmental Health Perspectives http://dx.doi.org/10.1289/ehp.1205266.
Publication date: December, 2012
Source: PBS To the Contrary
Publication date: April 19, 2013