Immune-Epigenetic Effects of Environmental Pollutants: Mechanisms, Biomarkers, and Transgenerational Impact

Environmental pollutants such as heavy metals, endocrine-disrupting chemicals, microplastics, and airborne particulates are increasingly recognized for their potential to influence immune function through epigenetic mechanisms. This review examines conserved pollutant-associated pathways at interfaces of immunity and epigenetics, with particular attention to Toll-like receptor-NF-κB signalling, NLRP3 inflammasome activity, and reactive oxygen species-driven cascades. Evidence from cellular, animal, and epidemiological studies indicates that these pathways may converge on chromatin regulators such as DNA methyltransferases, histone deacetylases, and EZH2, leading to DNA methylation shifts, histone modifications, and altered chromatin accessibility. Pollutants are also reported to modulate non-coding RNAs, including miR-21, miR-155, and several lncRNAs, which can act as intermediaries between cytokine signalling and epigenetic remodelling. Findings from transgenerational models suggest that pollutant-linked immune-epigenetic alterations might persist across generations, raising the possibility of long-term consequences for immune and neurodevelopmental health. Comparative analyses further indicate convergence across diverse pollutant classes, pointing to a shared mechanistic axis of immune-epigenetic disruption. Overall, these insights suggest that pollutant-induced immune-epigenetic signatures may contribute to inflammation, altered immune responses, and heritable disease risks, and their clarification could inform biomarker discovery and future precision approaches in immunotoxicology.