Exploring the association between early-life air pollution exposure and autism spectrum disorders in children: A systematic review and meta-analysis

The objective of this meta-analysis is to investigate the association between air pollution and the vulnerability of children to autism spectrum disorders (ASD). A thorough examination and analysis of data obtained from a compilation of 14 studies was undertaken, with a particular emphasis on investigating the effects of nitrogen dioxide (NO₂), oxide of nitrogen (NO_x), ozone (O₃), and particulate matter (PM₁₀ and PM_2.5) on individuals diagnosed with ASD. The findings demonstrate a moderate association between exposure to nitrogen dioxide (NO₂) and ASD, as indicated by a combined odds ratio (OR) of 1.13 and a 95% confidence interval (CI) spanning from 0.77 to 1.549. O₃ shows a combined odds ratio (OR) of 0.82, along with a 95% confidence interval (CI) ranging from 0.49 to 1.14. NO_x shows a moderate level of heterogeneity (I² = 75.9%, p = 0.002), suggesting that the impact of NO_x on the risk of ASD. There is a statistically significant relationship between exposure to O₃ and ASD, although the strength of this relationship is diminished. The findings demonstrated a noteworthy correlation between exposure to PM₁₀ and PM_2.5 and the occurrence of ASD. The study found a significant correlation, in relation to PM_2.5, with a combined odds ratio (OR) of 1.22 and a 95% confidence interval (CI) ranging from 1.11 to 1.34. The findings have significant implications for the formulation of programs aimed at reducing exposure to harmful chemicals, especially among vulnerable groups such as children.