The silent threat: PM2.5-associated challenges in male reproductive health.

Global fertility rates have exhibited a concerning decline, paralleling the public health challenges posed by fine particulate matter 2.5 (PM2.5) pollution. This comprehensive review synthesizes current evidence on the multiple impacts of PM2.5 exposure on male reproductive health, including epidemiological findings, mechanistic insights, and potential mitigation strategies, which have not been thoroughly evaluated in previous literature. Epidemiological evidence indicates a significant association between PM2.5 exposure and adverse male reproductive outcomes, including reduced fertility and adverse semen quality. The detrimental effects of PM2.5 are mediated through multiple biological pathways, particularly oxidative stress induction, disruption of mitochondrial and endoplasmic reticulum homeostasis, interference with endocrine signaling especially testosterone synthesis, and the promotion of harmful epigenetic modifications. These molecular and cellular alterations collectively impair spermatogenesis and overall reproductive function. Furthermore, this review discusses promising intervention approaches aimed at reducing the reproductive risks associated with PM2.5 exposure. By integrating epidemiological, experimental, and mechanistic evidence, the review underscores the critical connection between ambient air pollution and male reproductive dysfunction, highlighting the urgent need to enhance public awareness of the adverse effects of PM2.5 on male fertility and to promote effective protective measures.