Prenatal exposure to polybrominated diphenyl ethers (PBDEs) and cognitive ability in early childhood
- DOI
- Language of the publication
- English
- Date
- 2020-12-13
- Type
- Article
- Author(s)
- Azar, Naomi
- Booij, Linda
- Muckle, Gina
- Arbuckle, Tye E.
- Séguin, Jean R.
- Asztalos, Elizabeth
- Fraser, William D.
- Lanphear, Bruce P.
- Bouchard, Maryse F.
- Publisher
- Elsevier
Abstract
Background Prenatal exposure to polybrominated diphenyl ethers (PBDEs) has been associated with adverse neurodevelopmental outcomes in children, but evidence remains mixed regarding sex differences in this association. Objective To examine the prospective association between prenatal PBDE exposure and cognitive ability in young children, as well as potential sex differences. Methods The study was conducted in a multi-site Canadian pregnancy cohort recruited in 2008–11. PBDEs were measured in maternal plasma samples collected early in pregnancy. Cognitive ability was assessed using the Wechsler Preschool and Primary Scale of Intelligence (WPPSI-III) in children at age 3 years (mean = 3.4). Multiple linear regression was used to analyze the association between maternal PBDE plasma concentrations (lipid-standardized and log10-transformed) and Verbal, Performance, and Full Scale IQ scores on the whole sample and stratified by sex, adjusting for confounders. Results The sample was composed of 592 children (291 boys and 301 girls). A tenfold increase in maternal blood PBDE concentration (sum of BDE-47, −99, −100, and −153) was associated with lower Full Scale scores in boys (−3.4 points; 95% CI: −7.0, 0.1), after adjusting for confounders. BDE-47 was the congener with the highest concentrations in maternal blood and a tenfold increase in exposure was associated with significantly lower Full Scale IQ scores in boys (−4.4 points; 95% CI: −7.9, −0.9), after adjusting for confounders. Verbal and Performance IQ scores were similarly associated with PBDE exposure. Maternal blood PBDE concentrations were not associated with IQ scores in girls. Conclusions Prenatal exposure to background levels of PBDEs, especially BDE-47, was associated with lower IQ scores in boys, but not in girls. Our results support that exposure to PBDEs during early development may be sex-dependent and detrimental to a child’s neurodevelopmental trajectory.
Plain language summary
Health Canada is responsible for the assessment and management of health risks, including those associated with exposure to chemicals in the environment. Polybrominated Diphenyl Ethers (PBDEs) are commercially produced substances that are used as flame retardants in a wide variety of consumer products. Some research studies have reported associations between prenatal exposure to PBDEs and lower cognitive ability in children; however, whether this association differs between boys and girls is largely unknown. The goal of this study was to examine the association between prenatal exposure to PBDEs and cognitive ability in young boys and girls. In the MIREC Study, PBDEs were measured in maternal blood during early pregnancy. When the children were 3 years old, their IQ was measured to assess cognitive ability. Data were analyzed for 592 children. The study found that a tenfold increase in maternal PBDE concentration was associated with a small decrease of 3.4 points IQ in boys. No association was observed between prenatal PBDEs and IQ in girls. This study found that prenatal exposure to higher levels of PBDEs was associated with slightly lower IQ scores in boys but not girls. This study was led by a graduate student at the University of Montreal. The results of this study will help to inform Health Canada risk assessment and risk management activities as well as public health measures aimed at protecting this vulnerable population from the potential effects, if any, of exposure to environmental chemicals.
Subject
- Health,
- Health and safety