The widespread use of plastics has increased environmental pollution by micro- and nanoplastics (MNPs), especially polystyrene micro- and nanoplastics (PS-MNPs). These particles are persistent, bioaccumulative, and linked to endocrine-disrupting toxicity, posing risks to reproductive health. This review examines the effects of PS-MNPs on mammalian reproductive systems, focusing on oxidative stress, inflammation, and hormonal imbalances. A comprehensive search in the Web of Science Core Collection, following PRISMA 2020 guidelines, identified studies on the impact of PS-MNPs on mammalian fertility, including oogenesis, spermatogenesis, and folliculogenesis. An analysis of 194 publications revealed significant reproductive harm, such as reduced ovarian size, depleted follicular reserves, increased apoptosis in somatic cells, and disrupted estrous cycles in females, along with impaired sperm quality and hormonal imbalances in males. These effects were linked to endocrine disruption, oxidative stress, and inflammation, leading to cellular and molecular damage. Further research is urgently needed to understand PS-MNPs toxicity mechanisms, develop interventions, and assess long-term reproductive health impacts across generations, highlighting the need to address these challenges given the growing environmental exposure.
Keywords: PS-MNPs; antioxidants; endocrine disruption; female fertility; male fertility; mammals; reproductive health.