Maternal and early-life arsenic exposure and relative telomere length in children: Findings from the BiRCH cohort.

Arsenic exposure through drinking water remains a significant global public health concern and has been associated with a range of adverse health outcomes. Telomere(definition) length, a biomarker of cellular aging and genomic stability, may be influenced by arsenic-induced oxidative stress. However, limited research has evaluated the impact of arsenic exposure during critical developmental windows on telomere length in children. In this analysis, we examined associations between maternal and early-life arsenic exposure and relative telomere length (RTL) among 458 children aged 5 to 7 years participating in the Bangladesh Environmental Research in Children's Health (BiRCH) cohort. Maternal and child arsenic exposure was estimated from spot urine samples, and child RTL was measured in whole blood DNA using a Luminex-based assay. Arsenic exposure was categorized into tertiles to evaluate potential non-linear associations with RTL. Multivariable linear regression models were fit to estimate associations between maternal and child arsenic exposure and child RTL, adjusted for a priori covariates. Maternal arsenic exposure in the highest tertile was associated with shorter RTL compared to the lowest tertile (β = -0.045, 95% CI: -0.080, -0.011). This association remained significant, though slightly attenuated, after adjustment for child arsenic exposure (β = -0.040, 95% CI: -0.075, -0.005), suggesting an independent effect of maternal exposure. Our findings indicate that both maternal and child arsenic exposure may be associated with telomere attrition, with potential implications for long-term health. Further research is needed to elucidate the biological mechanisms and health consequences of early-life telomere shortening in arsenic-exposed populations.