The cumulative impact of fine particulate matter exposure on hippocampal volume and working memory: Insights from prenatal and adolescent exposures from the ABCD study.

BACKGROUND: Global warming, urbanization, coal-burning pollution, and global wildfires draw attention to the necessity of bridging gaps in our current understanding of the effects of fine particulate matter (PM2.5) on neurodevelopment. Despite evidence of environmental contaminants having deleterious effects on cognition and neurodevelopment in particularly sensitive areas like the hippocampus that have prolonged plasticity, much of this work examines a single time point (e.g., prenatal exposure) in single site studies. As a result, it is unclear whether deleterious effects accumulate over development. METHODS: The Adolescent Brain Cognitive Development study (aged 8.9-11.1 years; 47.1 % female) provides a geographically broad and racially diverse sample (66.1 % White, 20.7 % Black, 13.2 % Multiple/Other). This study also includes prenatal and late childhood measures of PM2.5 and ozone (O3) as well as hippocampal volume (n = 6553), hippocampal function (n = 5556), and related cognition (n = 6418). RESULTS: Adjusted associations of PM2.5 exposure were associated with smaller hippocampal volumes and less accurate working memory performance; this association was stronger for youth exposed to relatively higher PM2.5 during both prenatal and late childhood periods as compared to lower PM2.5 categories. CONCLUSIONS: Results support exposure to PM2.5 during prenatal and late childhood periods could have cumulative links to altered neural structure and executive function during sensitive periods of development. Study findings could inform physical environment health promoting prevention and intervention policy efforts.