Cytotoxicity And DNA Damage Of Water-soluble Fraction In Fuel Oil And Oil Spill Dispersant On Juvenile Paralichthys Olivaceus

Spilled oil pollution in marine ecosystem has been a serious environmental problem, which has caused great concern throughout the world. In order to investigate the toxic effects of water-soluble fraction in fuel oil and oil spill dispersant on marine fishes, percentage composition of main n-alkanes and main polycyclic aromatic hydrocarbon in 180CST fuel oil were analyzed under laboratoey conditions, the juvenile Paralichthys olivaceus was exposed to water-soluble fraction in 180CST fuel oil(WAF), GM-2 oil spill dispersant(GM-2) and fuel oil spill dispersant mixed solution(DWAF). Superoxide dismutase (SOD), catalase (CAT), peroxidase (POD) and glutathione S-transferases (GST), Malondialdehyde (MDA) in liver and gill and red retention time assay (NRRT) of blood cells were measured in exposed time of 0,3,7,15 days and removed pollution time of 6 days, DNA damage was assessed by the comet assay performed on blood cells in exposed time of 15 days and removed pollution time of 6 days.The mainly results are following:1 Percentage composition of main n-alkanes and main polycyclic aromatic hydrocarbon in 180CST fuel oilPercentage composition of main n-alkanes in 180CST fuel oil was 83.46%, percentage composition of main polycyclic aromatic hydrocarbon was 4.35%.2 Cytotoxicity and DNA Damage of Water-Soluble Fraction in Fuel Oil on juvenile P. OlivaceusAntioxidant enzyme activities and MDA contents in liver and gill of juvenile P. olivaceus had different responses to the stress of water-solution fraction in fuel oil. And activities of the single enzyme were also diverse at different time. Integrated biomarker response index (IBR) was employed to evaluate the toxic effects of water-soluble fraction in fuel oil on juvenile P.olivaceus, results indicated that the higher concentration of water-soluble fraction in fuel oil was, the more toxic effects it had on juvenile P.olivaceus. Moreover, the lysosomal membrane stability (LMS) of hemocyte decreased significantly (P<0.05) with increasing concentrations of fuel oil. After a 6-day recovery period, the LMS in 0.001mg/L concentration group restored to the control level(P>0.05), whereas they were still significantly lower (P<0.05) in 0.010 mg/L and 0.100 mg/L concentration groups. A 15-dayexposure period of fuel oil could cause moderate DNA damage in 0.001 mg/L and 0.010 mg/L concentration groups, and serious DNA damage in 0.100 mg/L concentration group. However, after a 6-day recovery period, DNA damage has been recovered but still significantly higher (P<0.05) than control level.3 Cytotoxicity and DNA Damage of oil spill dispersant on juvenile P. olivaceusAntioxidant enzyme activities and MDA contents in liver and gill of juvenile P. olivaceus had different responses to the stress of water-solution fraction in fuel oil and oil spill dispersant. IBR was employed to evaluate the toxic effects of water-soluble fraction in fuel oil and oil spill dispersant on juvenile P.olivaceus, results indicated that fuel oil was more toxic to juvenile P.olivaceus than oil spill dispersant. Results of the LMS indicated that oil spill dispersant had certain toxicity on juvenile P. olivaceus, but much less than fuel oil, the usage of oil spill dispersant could reduce the toxicity of fuel oil on juvenile P. olivaceus. and reduce DNA damage caused by oil spill to juvenile P. olivaceus, but may damage the self-repairing function of DNA.