Prenatal DEHP exposure linked to autism and ADHD symptoms in study

A study of 847 Australian mother-infant pairs found that higher prenatal exposure to the plastic additive DEHP was associated with more autism- and ADHD-related symptoms at ages two and four, with epigenetic changes in cord blood. The observational research, published in Med, adds to evidence on environmental factors in neurodevelopment but cannot prove causation.

Bottom line — The study identified an epigenetic signature in 531 genes mediating 21% of the link, with clearer effects in males.

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• DEHP (di-(2-ethylhexyl) phthalate) is a common plasticiser used in vinyl furniture, garden hoses, shower curtains, medical tubing, and vegan leathers, per ScienceAlert.
• Lead author Sam Tanner, a bioinformatics analyst at the University of Melbourne, said the findings provide 'a possible biological explanation' that DEHP exposure in pregnancy may contribute to autism and ADHD.
• The study drew on data from the Barwon Infant Study; mothers provided a urine sample at 36 weeks to estimate DEHP intake, and umbilical cord blood was analysed for DNA methylation patterns.
• Researchers found that a group of 531 genes affected by methylation appeared to mediate 21% of the link between estimated DEHP exposure and behavioural symptoms, according to ScienceAlert.
• Medical researcher Mirko Uljarevic, not involved in the study, cautioned that the behavioural measures were not clinical diagnoses and that autism and ADHD arise from many genetic and environmental factors, making a single exposure unlikely to meaningfully change an individual child's risk.
• The study is observational and cannot prove cause and effect; the authors could not test the full chain from chemical exposure to brain changes to symptoms, Uljarevic added.

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