Maternal exposure to fine particulate matter and autism spectrum disorder in children: population based case-control...

Autism spectrum disorder (ASD) is a pervasive neurodevelopmental disorder that can develop in infancy and is caused by a combination of genetic predisposition and environmental factors. Fine particulate matter (PM_2.5) is one of the most dangerous air pollutants, capable of carrying various toxic substances deep into body tissues and causing complex health effects. Exposure to PM_2.5 during pregnancy may increase the risk of neurodevelopmental disorders in offspring. This study aimed to investigate the association between maternal exposure to PM_2.5 and its major components during pregnancy and childhood ASD, and to identify critical gestational windows of vulnerability.

All participants were recruited exclusively from the Xinyang Central Hospital, and covariates were ascertained through structured clinical interviews. PM_2.5 and its components, including sulfate ( ${\mathrm{SO}}_4^{2-}$ ), nitrate ( ${\mathrm{NO}}_3^{-}$ ), ammonium ( ${\mathrm{NH}}_4^{+}$ ), organic matter (OM), and black carbon (BC), were derived from Tracking Air Pollution in China (TAP). Statistical analysis was performed using SPSS, employing the chi-square test, rank-sum test, and binary logistic regression analysis.

Positive associations were observed between PM_2.5 and ASD (OR = 5.197, 95% CI: 3.294-8.200), and between ${\mathrm{SO}}_4^{2-}$ , ${\mathrm{NO}}_3^{-}$ , ${\mathrm{NH}}_4^{+}$ , BC, and OM and ASD. Monthly risk estimates for all pollutants exhibited a right-skewed distribution, with the strongest associations consistently observed during the gestational months 4-7.

Maternal exposure to PM_2.5, ${\mathrm{SO}}_4^{2-}$ , ${\mathrm{NO}}_3^{-}$ , ${\mathrm{NH}}_4^{+}$ , BC, and OM was associated with ASD in children, particularly ${\mathrm{SO}}_4^{2-}$ and BC. The 4th-7th gestational months represent a critical window of vulnerability. These findings support targeted public health interventions to reduce prenatal air pollution exposure.