Oxidative Stress, Environmental Pollutants, Aging, and Epigenetic Regulation: Mechanistic Insights and Biomarker Advances

Environmental pollutants, lifestyle factors, and intrinsic metabolic activity converge to generate an imbalance between reactive oxygen species (ROS) production and the capacity of antioxidant defense systems. This oxidative stress damages cellular macromolecules, reprograms gene expression, and accelerates aging. Here we synthesize recent evidence (2020–2025) on the mechanisms by which air pollutants, heavy metals, pesticides, nanoparticles, and microplastics generate ROS, how redox imbalance interfaces with epigenetic regulation, and how these processes drive aging and disease. Rather than condensing, we retain full mechanistic details from multiple recent reviews to provide a comprehensive resource. We also discuss emerging biomarkers, including redox‑related metabolites and epigenetic signatures, and outline future directions for integrating multi‑omics and artificial intelligence to develop personalized interventions. Citation numbering in the text follows the order of appearance.