The burden of autism spectrum disorder (ASD) is increasing worldwide with genetic, epigenetic, and environmental factors being possibly responsible for the observed epidemiological figures. In the setting of environmental exposure, the city of Taranto, in Southern Italy, represents an interesting case study as it hosts well inside the city one of the biggest steel plants in Europe. This is a cross-sectional ecological study carried out in the year 2020 in the province of Taranto designed to estimate the burden of ASD in the municipalities of Taranto and Statte, classified as high environmental risk areas (Contaminated Site of National Interest-SIN), compared to the other 27 municipalities of the same province. Differences have been evaluated using the Chi Square Test. Children aged 6-11 years identified in SIN municipalities had a statistically significant higher prevalence of ASD than children of other municipalities (9.58 vs. 6.66/1000 respectively, p = 0.002). No statistically significant difference was observed for the 12-18 years group (3.41 vs. 2.54/1000, p = 0.12). The findings observed in this study are suggestive of the association between urban residential proximity to industrial facilities emitting air pollutants and higher ASD prevalence.
