Genome-wide DNA methylation association study of recent and accumulated ozone exposure in the National Longitudinal Study of Adolescent to Adult Health (Add Health) Study.

Ground-level ozone exposure poses a significant public health threat, linked to respiratory problems, cardiovascular disease, and cognitive decline. Emerging evidence suggests that DNA methylation (DNAm) alterations, a form of epigenetic modification, may contribute to these health effects. Here, we conducted an epigenome-wide association study (EWAS) involving 4500 adults aged 32-42 years from diverse populations across the United States to explore how recent (past year) and accumulated (past 14 years) ozone exposure relate to DNAm patterns. We identified six CpGs that reached epigenome-wide significance, with five associated with recent ozone exposure and one with accumulated exposure. Sensitivity analyses confirmed the robustness of our findings, adjusting for potential confounders including smoking, alcohol use, body mass index (BMI), income, and education. By comparing the DNAm signatures to ozone longitudinal histories, we confirmed the long-term association between ozone exposures and DNAm and the extent to which these DNAm changes may be reversible over time. We observed that differential DNAm responses varied in their consistency across different genetic ancestry groups. These findings deepen our understanding of ozone's long-term health implications through epigenetic mechanisms and its reversibility with the duration of ozone exposures, suggesting potential biomarkers and pathways for targeted interventions.

Duke Scholars

Author Mercedes A Bravo Duke Global Health Institute