Complex Toxic Impacts Of Heavy Metals And Benzo(a)pyrene On Marine Mussels

This study focused on the complex toxic impacts of typical environmental pollutants,such as heavy metals(Cu,Zn,Cd,Pb)and organic pollutants(PCBs and BaP)on marine mussels(Mytilus galloprovincialis).Genotoxic effects including DNA damage and micronuclei frequency induced by heavy metals and PCBs were assessed in vitro using freshly isolated haemocytes,gill and digestive gland cells.Gill cells showed more sensitive to Zn and Cu exposure among three types of cells,indicating tissue-specific genotoxicity.An increased toxic effect was detected after combined heavy metals and PCBs exposure,suggesting the synergistic toxic effects induced by the interaction of complex pollutants.In order to better understand the toxic effects induced by heavy metals and BaP in mussels after the biotransformation and biometabolism processes,an in vivo experiment system was applied by using individual mussels.Significantly increased genotoxicity in different tissue cells and decreased thickness of digestive gland epithelial layer were detected with prolonged exposure time,suggesting time-dependent response in mussels.Toxic effects were different among various combined exposure conditions,indicating the interactions between diverse pollutants were associated with the innate physical and chemical characteristics.The results of short-time in vivo experiment and in vitro experiment showed consistent results by comparing the genotoxic effects induced by the same heavy metals,which is further verified the proposed scenario that isolated mussel cells can be used as possible environmental monitoring tool in the future.To our knowledge,this is the first research to include both in vivo and in vitro exposure together with the purpose of exploring the complex toxic effects of heavy metals and organic pollutants at different biological levels and tissues of marine mussels.This research provides not only scientific data to investigate the potential xenobiotics metabolic mechanisms but also theoretical foundation for developing a rapid environmental monitoring tool by using isolated cells from marine organisms.