Developing an Early Childhood Environmental Health Vulnerability Index to Assess Cumulative Health Impacts Across Contiguous US

Abstract

Young children (birth to age five) are uniquely vulnerable to environmental hazards due to their higher exposure relative to body weight, rapid physiological and neurological development, and strong reliance on caregivers for protection and care. Such risks are often amplified in marginalized communities with socioeconomic disadvantage and limited access to resources. However, widely used indices, such as the Social Vulnerability Index (SVI), the Climate Vulnerability Index (CVI), and the Child Opportunity Index (COI), were not specifically developed for young children and may not capture the combined environmental and socioeconomic risks faced by this age group. To address this critical gap, we developed a county‐level Early Childhood Environmental Health Vulnerability Index (EC‐EHVI) for the contiguous US using multidimensional indicators within an Exposure‐Sensitivity‐Adaptive Capacity framework and informed by Bronfenbrenner's bioecological model. We identified the underlying drivers and the spatial patterns of the EC‐EHVI. Our results showed that the EC‐EHVI exhibited the strongest association with county‐level mortality among young children and explained a larger proportion of spatial heterogeneity compared with the SVI, CVI, and COI. Elevated vulnerability clustered in the Great Plains and Southeastern US, where over half of high‐vulnerability counties were exposure‐driven, and 411 high–high hotspots were identified. The EC‐EHVI offers a valuable spatial decision‐support tool for designing targeted, place‐based interventions and advancing environmental health equity for young children.