Emerging contaminants (ECs), including pharmaceuticals, microplastics, and per- and polyfluoroalkyl substances (PFAS), have become ubiquitous in air, water, and soil, posing hidden threats to public health. This study integrates exposomics, environmental epidemiology, and toxicology to explore EC exposure pathways, biological mechanisms of toxicity, and health impacts (e.g., endocrine disruption, cardiovascular diseases, and developmental disorders). Innovative analytical methods (e.g., high-resolution mass spectrometry) and AI-driven environmental modeling were applied to quantify EC concentrations in different matrices and predict population exposure risks. Additionally, we assessed the role of climate change in altering EC distribution and the health co-benefits of carbon neutralization initiatives. Finally, this paper proposes targeted policies (e.g., stricter emission standards) and technological innovations (e.g., advanced water treatment) to mitigate EC risks, highlighting the need for international collaboration in environmental health governance.