Wastewater-based surveillance for community exposome surveillance, Louisville, Kentucky

Exposomics research has primarily focused on individual exposures relevant to precision environmental health. Community exposomics is an emerging concept that seeks to connect community-level exposures to public health, but clear, practical ways to scale surveillance from individuals to communities—especially using wastewater to determine community chemical exposures—remain limited. We address this issue by applying wastewater-based surveillance for community exposome surveillance, allowing detection of neighborhood- and multi-neighborhood-scale exposure to environmental toxicants. Influent wastewater samples from 24 sites and tap water samples from five sites in the same areas were analyzed using an Inductively Coupled Plasma Quadrupole Mass Spectrometer to quantify 26 metals. Exposure levels vary across the county: 20 of 24 sites had at least one metal level exceeding 1 standard deviation (SD) above the mean and were designated areas of concern. Additionally, 14 of the 20 sites were designated as having increased concern, with levels greater than 2 SD above the mean. Our findings contribute to a better understanding of how wastewater-based surveillance can serve as a tool for transitioning from individual- to community-scale exposome assessment, with neighborhood- and multi-neighborhood-scale metal variance observed across a single county. A place-based community health exposomics surveillance model that leverages wastewater may be a promising approach for future public health action.