Abstract: Male infertility is a growing global health concern, with environmental toxins increasingly recognized as significant contributors. Among the many mechanisms through which these toxicants exert their detrimental effects, epigenetic modifications—heritable changes in gene expression without alterations in DNA sequence—are emerging as critical mediators. This review provides a comprehensive examination of current evidence linking environmental toxins to epigenetic disruptions in the male reproductive system. Specifically, it explores how exposures to heavy metals, endocrine-disrupting chemicals (EDCs), air pollutants, and pesticides can alter DNA methylation patterns, histone modifications, and non-coding RNA expression in sperm and testicular tissue. These epigenetic changes have been associated with impaired spermatogenesis, reduced sperm quality, hormonal imbalances, and even transgenerational reproductive effects. Additionally, the review discusses the molecular pathways affected by these modifications, potential biomarkers for exposure and infertility, and the reversibility of some epigenetic damage through lifestyle changes and medical interventions. Understanding these interactions is crucial for developing effective public health strategies and personalized approaches to diagnose, prevent, and manage environmentally induced male infertility.

Keywords: Male infertility, Epigenetics, Environmental toxins, DNA methylation, Histone modification, Air pollution, Sperm quality.