A study by the Florey Institute in Melbourne has revealed a significant association between prenatal exposure to the plastic chemical bisphenol A (BPA) and autism symptoms in boys. The research indicates that boys born to mothers with high BPA levels in late pregnancy are 3.5 times more likely to exhibit autism symptoms by age two and six times more likely to receive a verified autism diagnosis by age eleven. The study emphasizes that BPA disrupts male fetal brain development by silencing the enzyme aromatase, which plays a crucial role in neurohormonal regulation. Although the findings suggest BPA may be a contributing factor, Professor Anne-Louise Ponsonby clarifies that autism is multifactorial, involving various genetic and environmental influences. The research analyzed data from two large cohorts, the Barwon Infant Study in Australia and the Columbia Centre for Children’s Health and Environment in the USA, supporting the hypothesis that plastic chemicals in the womb may impact neurodevelopment. This groundbreaking work adds to the growing body of evidence linking environmental exposures during pregnancy to autism risk.