Exposomics as a discovery engine for emerging contaminants and hidden biological risks.

Over the past decade, exposome science has evolved from a conceptual framework into a practical discovery engine for environmental health. By combining high-resolution mass spectrometry, non-targeted analysis, multi-omics integration, wearable sensors, and computational tools, exposomics can capture the complexity of real-world chemical mixtures and uncover exposures missed by conventional monitoring. We conducted a scoping review following PRISMA-ScR guidelines to map how exposomic approaches have been applied to the detection and characterisation of under-regulated or previously unknown contaminants. Searches of four bibliographic databases and targeted grey literature (2015-2025) yielded 67 eligible studies, of which 42 were charted quantitatively. The evidence was heavily concentrated in high-income countries and focused on pesticides, PFAS, and heavy metals, with metabolic, developmental, and epigenetic outcomes most frequently reported. Across this landscape, 17 priority compounds emerged where exposomics revealed either new detections or novel biological effects, including halobenzoquinones, GenX, bisphenol S, microplastics, tungsten, and 3-hydroxyoctanedioic acid. These case exemplars illustrate how exposomics can expand hazard characterisation and provide early warning of risks that are invisible to targeted surveillance. At the same time, critical gaps persist, particularly in geographic coverage, longitudinal cohorts, data infrastructures, and mixture analysis tools. Scaling exposomics through harmonised biomonitoring systems and embedding it within One Health frameworks will be essential to accelerate discovery and to translate emerging evidence into more proactive and equitable chemical risk governance.