Prenatal exposure to benzene, toluene, ethylbenzene, and xylene (BTEX) and the risk of autism spectrum disorders in children aged 16-37 months: A prospective cohort study.

Autism spectrum disorder (ASD) as a neurological disorder can result from the interaction of genetic and environmental factors such as air pollution and exposure to chemical pollutants. This study tested the hypothesis that living in areas near petrochemical industries and exposure to benzene, toluene, ethylbenzene, and xylene (BTEX) may adversely affect maternal and fetal health and increase the risk of autism. We conducted a prospective cohort study from 2019 to 2024, following 110 pregnant women divided into exposure and control groups, along with 145 children born during the study [exposure group (n = 80) and control group (n = 65)]. Prenatal urinary BTEX concentrations were measured using gas chromatography-mass spectrometry (GC/MS). The MCHAT-R/F screening tool was used to track the child's behavior in terms of the occurrence of autism spectrum symptoms. The results showed that the mean concentration of prenatal BTEX urine concentration in the exposed group (557 ng/l) was significantly higher than that in the control group (258 ng/l). The M-CHAT-R/F screening indicated moderate ASD risk in six exposure group children and three control group children; and high ASD risk for four exposure group children and one control group child. The findings in the exposure group revealed a higher incidence of ASD among boys compared to girls (4:2 in medium risk and 3:1 in high risk). Multivariate logistic regression analysis indicated that the prevalence of autism in the exposed group was significantly associated with exposure to benzene (OR, 2.10; 95%CI, 1.93-2.17; P<0.05) and toluene (OR, 1.7; 95%CI, 1.62-1.81; P<0.05). Living in industrial areas and perinatal exposure to BTEX compounds may increase the risk of ASD. Therefore, health impact assessment studies focusing on the health of vulnerable groups before the construction of petrochemical industries, as well as the monitoring of relevant health indices during the operational phase, should be prioritized.