Defining the external exposome of newborns from La Palma Island, Spain: characteristics of realistic mixtures and its role on Precision Public Health

Abstract

Introduction : The exposome framework provides an integrative perspective to characterize real-life exposures beyond single-chemical assessments. However, evidence on perinatal exposomes in non-urban populations is limited, particularly regarding pollutant mixtures and their contribution to adverse birth outcomes. Methods : We conducted a population-based cross-sectional study including 471 neonates from La Palma (Spain). A total of 106 pollutants were quantified in cord blood using validated methods. Exposures encompassed essential elements, toxic metals, prioritized pollutants, emerging elements, organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), and polycyclic aromatic hydrocarbons (PAHs), grouped into seven categories. Statistical analyses included descriptive statistics, correlation matrices, principal component analysis (PCA), and network visualization, stratified by sex, birthweight, and maternal smoking. Results : Essential elements (Se, Zn, Cu, Mn) were detected in all samples, whereas emerging rare earth elements showed lower prevalence. PCA highlighted distinct exposure profiles, with PAHs and OCPs explaining the highest variance. Maternal smoking strongly influenced clustering: small for gestational age neonates from smoking mothers displayed a specific mixture of PAHs, OCPs, low-chlorinated PCBs, and Pb, contrasting with neonates of appropriate or large for gestational age. Network analyses revealed four main pollutant clusters, diverging from the seven predefined chemical groups and reflecting real-world mixtures shaped by common sources. Emerging pollutants, including rare earth elements and metals from electronic waste, formed a separate cluster. Conclusion : Exposome-based approaches can characterize neonatal exposure mixtures, reveal modifiable patterns, and inform targeted interventions within Precision Public Health. These findings underscore the need to mitigate maternal smoking and address emerging contaminant exposures in perinatal populations.