Chronic exposure to organic oxygen-demanding pollutants at an environmentally realistic concentration affects sperm...

Wastewater and organic oxygen-demanding pollutants (ODPs) are produced by various factories in China, the United States and other countries. However, whether ODP affects reproductive health remains unclear. To investigate the impact of environmental concentrations of ODP exposure on reproductive health, adult male zebrafish were used to evaluated the effects ODP exposure on the fertility in this study. We found that exposure to ODP reduced the sperm motility of adult male zebrafish. Similarly, the testosterone content of the experimental zebrafish was obviously decreased. Transcription of immune response-related genes, including tumor necrosis factor (tnf)-α, il-1β, and il-8, was upregulated upon exposure to ODP. Mating experiments indicated that the hatching time of the offspring embryos was clearly prolonged upon ODP exposure, but the embryo fertilization rate was not different. These results assumed that exposure to ODP at ambient concentrations visibly affected the sperm motility in adult zebrafish maybe due to the expression of immune response-related genes in the zebrafish male gonads and the release of pro-inflammatory mediators. Therefore, we assumed that the impact of ODP on the reproductive health of aquatic organisms cannot be ignored.