Correlates of prenatal heavy metal contamination in Lebanese infants using cord blood analysis

Exposure to heavy metals during pregnancy can disrupt fetal development and cause adverse health effects. However, data on fetal exposure in Lebanon remain scarce. The Environmental Exposures in Lebanese Infants (EELI) Study, a longitudinal birth cohort launched in 2021, investigates early-life environmental exposures among Lebanese infants. This study assesses the levels of 8 toxic (antimony, arsenic, chromium, nickel, cadmium, mercury, thallium, and lead) and 6 essential heavy metals (molybdenum, manganese, cobalt, copper, zinc, and selenium) in cord blood samples (N = 74). Descriptive statistics were used to characterize metal concentrations, and bivariate and multivariate analyses were conducted to examine associations with selected sociodemographic, environmental, health-related, and dietary factors. All toxic heavy metals were detected in cord blood samples, indicating prenatal exposure. Lead (md: 5.45 µg/L, p95: 22.4 µg/L) and mercury (md: 0.7 µg/L, p95: 2.01 µg/L) were among the highest detected toxicants. Essential metals such as zinc, copper, and manganese exhibited the highest variability. Several contextual factors, including residential proximity to highways, parking lots, and industrial areas, home renovations, energy sources, and pesticide use, were statistically associated with variations in cord blood metal concentrations. While causal inference cannot be established, this study underscores the importance of documenting early-life exposure patterns to inform future research into the developmental origin of health and diseases in resource-limited settings.