Microplastics in ovarian function and ozone-based mitigation strategies: Emerging evidence and translational implications

Microplastics (MPs) are now recognized as pervasive environmental contaminants with emerging evidence of bioaccumulation in the human reproductive system. Recent studies have detected MPs in human follicular fluid, oocytes, placenta, and semen, raising concerns about potential effects on fertility, gamete quality, and embryo development. Experimental data from animal models and in vitro human studies demonstrate that MPs can induce oxidative stress, mitochondrial dysfunction, meiotic spindle disruption, and apoptosis, ultimately impairing fertilization and developmental potential. These findings underscore the urgency of identifying effective strategies to reduce human exposure. Ozone-based water and wastewater treatment technologies are gaining attention as a means to mitigate environmental MPs before human ingestion or contact. Laboratory, pilot-scale, and full-scale plant studies show that ozonation-alone or in combination with granular activated carbon (GAC), coagulation-flocculation, sand filtration, or catalytic oxidation-can remove or degrade a substantial proportion of MPs (up to 96%), with smaller particles often removed more efficiently. Ozone induces surface oxidation and increases hydrophilicity, promoting aggregation and facilitating downstream filtration or sedimentation. While ozonation is less effective than some advanced oxidation processes in complete degradation, it offers the advantage of integration into existing treatment infrastructure. This review synthesizes current knowledge on MPs in ovarian health and the role of ozone-based treatments in limiting exposure. It discusses detection in the ovaries, mechanisms of reproductive toxicity, and the latest engineering strategies for MP removal, with a focus on translational implications for protecting fertility. Despite promising developments, significant gaps remain in linking environmental MP reduction directly to reproductive outcomes. Multidisciplinary collaboration between environmental engineers, reproductive biologists, and clinicians is essential to close these gaps and develop evidence-based public health interventions.