Micro- and nanoplastics (MNPs), as emerging environmental pollutants, have ubiquitously contaminated global ecosystems and even human tissues, raising significant concerns about their potential health risks. The global decline in male reproductive health, particularly semen quality, is thought to be strongly linked to environmental pollutant exposure. This review summarized the latest research progress on the effects of MNP exposure on male semen quality and its underlying mechanisms. Existing evidence indicates that MNPs can enter the human body through multiple pathways such as inhalation and ingestion, accumulate in the reproductive system including the testes and semen. This accumulation is associated with the deterioration of semen quality parameters, manifesting as decreased sperm concentration, reduced sperm motility, and abnormal sperm morphology. The proposed mechanisms primarily include oxidative stress, inflammatory response, endocrine disruption, and apoptosis. This paper systematically reviewed the findings and limitations of current research and provided perspectives on future directions, including the effects of long-term low-dose exposure, validation in human epidemiological studies, and the risks of mixed exposures, to provide a scientific basis for a comprehensive assessment of the male reproductive toxicity of MNPs.

Micro- and nanoplastics (MNPs), as emerging environmental pollutants, have ubiquitously contaminated global ecosystems and even human tissues, raising significant concerns about their potential health risks. The global decline in male reproductive health, particularly semen quality, is thought to be strongly linked to environmental pollutant exposure. This review summarized the latest research progress on the effects of MNP exposure on male semen quality and its underlying mechanisms. Existing evidence indicates that MNPs can enter the human body through multiple pathways such as inhalation and ingestion, accumulate in the reproductive system including the testes and semen. This accumulation is associated with the deterioration of semen quality parameters, manifesting as decreased sperm concentration, reduced sperm motility, and abnormal sperm morphology. The proposed mechanisms primarily include oxidative stress, inflammatory response, endocrine disruption, and apoptosis. This paper systematically reviewed the findings and limitations of current research and provided perspectives on future directions, including the effects of long-term low-dose exposure, validation in human epidemiological studies, and the risks of mixed exposures, to provide a scientific basis for a comprehensive assessment of the male reproductive toxicity of MNPs.