Association Between Prenatal Air Pollution Exposure and Autism in Children: EPINED Study

Air pollutants are emerging as recognised contributing factors in the aetiology of neurodevelopmental disorders, particularly increasing the risk of autism in children. This study explored the association between prenatal exposure to air pollutants and the likelihood of developing autism, considering both autistic symptoms and diagnosed cases in a school-based population from Tarragona (Spain), a province with extensive petrochemical activity.

In the first phase, parents and teachers of 3,727 children (aged 4 and 11 years) completed screening questionnaires (CAST and EDUTEA, respectively). In the second phase, 623 children were individually assessed, and diagnoses were based on DSM-5 criteria (58 children with autism and 51 with subthreshold autistic traits).

We performed multiple regressions, adjusting for individual, social, and family covariates. Significant associations were found between exposure to PM_coarse (β-0.16; CI: 0.03-0.29), NO₂ (β-0.15; CI: 0.02-0.28), and NO_x (β-0.18; CI: 0.03-0.34) and autism symptom scores reported by the teachers. Furthermore, a significant association suggests higher exposure to PM_2.5 (OR-1.66; CI: 1.03-2.65) and PM₁₀ (OR-1.46; CI: 1.01-2.12) during the second trimester of pregnancy can lead to higher chances of developing autism + subthreshold autistic traits in children.

These findings emphasise the potential impact of specific air pollutants, particularly during critical periods of pregnancy and foetal development, highlighting the need to explore further the role of air pollutants associated with the increased likelihood of autism in children.