Co-exposure to polystyrene nanoplastics and 3, 3', 4, 4', 5-pentachlorobiphenyl induces synergistic toxicity in human sperm

Growing evidence links environmental pollutant exposure to the deterioration of male reproductive health. In this study, the interactive toxicity between polystyrene nanoplastics (PS-NPs) and 3,3',4,4',5-pentachlorobiphenyl on human sperm functions were evaluated. Functional assays were performed on sperm in vitro from healthy volunteers treated separately or jointly with PS-NPs and PCB-126. Key endpoints-motility, cervical mucus-penetrating ability, capacitation, acrosome reaction, intracellular reactive oxygen species, and mitochondrial membrane potential-were significantly more impaired under co-exposure conditions than with individual treatments. Notably, combined treatment synergistically increased ROS accumulation, enhanced mitochondrial depolarization, and inhibited progesterone-stimulated capacitation and acrosome reaction of human sperm. The observed synergistic toxicity may be mediated through oxidative stress and disruption of mitochondrial function, leading to apoptotic-like changes. These results draw attention to the reproductive risks that may emerge from dual exposure to nanoplastics and stable organic environmental chemicals within the setting of idiopathic male infertility.