Research Finds Mixed Results with Metals, Pesticides, and Air Pollution and Calls for Further Research on Gender Differences and Exposure Timing
A new scientific review claims to be the first to systematically examine the impact of various environmental pollutants on autism spectrum disorder (ASD) and other neurodevelopmental disorders (NDDs). The review found associations between several pollutants and increased risk of these disorders, though the results were often inconsistent due to the poor quality of many studies. Specifically, metals such as arsenic, lead, and mercury were linked to ASD. Notably, this research revealed that higher levels of mercury, often attributed to seafood consumption, were associated with a potentially protective effect against ASD, particularly in boys. The authors suggested this association may be due to beneficial nutrients in seafood, such as polyunsaturated fatty acids, which support brain development. However, this finding is in direct opposition to previous reviews that discovered links between mercury exposure and the development of ASD. Additionally, this research showed that pesticides were also associated with increased risks of ASD and ADHD, with results varying by the timing of exposure and study methods. Air pollutants, particularly particulate matter (PM10), were linked to higher ASD risk, especially with exposure during the prenatal and early postnatal periods. The authors indicate that their review highlights the need for more research to investigate the combined effects of multiple pollutants, consider gender differences, and identify critical exposure periods to better understand and mitigate the risks of environmental contaminants for NDDs.
