Association Between Gestational Exposure to Toxicants and Autistic Behaviors Using Bayesian Quantile Regression
- DOI
- Language of the publication
- English
- Date
- 2021-03-29
- Type
- Article
- Author(s)
- Alampi, Joshua D.
- Lanphear, Bruce P.
- Braun, Joseph M.
- Chen, Aimin
- Takaro, Tim K.
- Muckle, Gina
- Arbuckle, Tye E.
- McCandless, Lawrence C.
- Publisher
- Oxford University Press
Abstract
Autism spectrum disorder, which is characterized by impaired social communication and stereotypic behaviors, affects 1%–2% of children. Although prenatal exposure to toxicants has been associated with autistic behaviors, most studies have been focused on shifts in mean behavior scores. We used Bayesian quantile regression to assess the associations between log2-transformed toxicant concentrations and autistic behaviors across the distribution of behaviors. We used data from the Maternal–Infant Research on Environmental Chemicals study, a pan-Canadian cohort (2008–2011). We measured metal, pesticide, polychlorinated biphenyl, phthalate, bisphenol-A, and triclosan concentrations in blood or urine samples collected during the first trimester of pregnancy. Using the Social Responsiveness Scale (SRS), in which higher scores denote more autistic-like behaviors, autistic behaviors were assessed in 478 children aged 3–4 years old. Lead, cadmium, and most phthalate metabolites were associated with mild increases in SRS scores at the 90th percentile of the SRS distribution. Manganese and some pesticides were associated with mild decreases in SRS scores at the 90th percentile of the SRS distribution. We identified several monotonic trends in which associations increased in magnitude from the bottom to the top of the SRS distribution. These results suggest that quantile regression can reveal nuanced relationships and, thus, should be more widely used by epidemiologists.
Plain language summary
Health Canada helps to protect the health of Canadians by assessing and managing the health risks associated with exposure to environmental contaminants. Phthalates are a group of chemicals used to make plastics more flexible and harder to break or as solvents (dissolving agents) for other materials. Lead, cadmium and manganese are metals. Cotinine is an indicator of exposure to tobacco smoke. A number of studies have reported associations between prenatal exposure to some chemicals and adverse effects on child behaviour. Autism Spectrum Disorder (ASD) impacts how a person perceives and socializes with others, causing problems in social interaction and communication. 1 in 66 Canadian children and youth (ages 5-17) are diagnosed with ASD, making ASD one of the most common developmental disabilities. In this analysis of data from the Maternal-Infant Research on Environmental Chemicals (MIREC) study, a complex statistical method was used to assess associations between various chemicals and autistic behaviors. Chemicals were measured in 1st trimester urine or blood of women in the MIREC Study. Autistic behaviors were assessed in their 3-4-year-old children (n=478) using the Social Responsiveness Scale (SRS). Higher scores meant more autistic-like behaviors. This study observed that among children with the highest SRS scores, lead, cadmium, cotinine, and several phthalates were associated with small to moderate increases in SRS scores. Manganese and some pesticides were associated with small to moderate decreases in SRS scores. As this study was the first to use this complex statistical method, additional studies are necessary to confirm these results.
Subject
- Health,
- Health and safety