Oxidatiev Damage Of PFOS To Chlorella And Earthworm

In this paper, using chlorella vlgaris and eisenia fitida as model organism, we studied the effects of PFOS on the chlorophyll content, cell permeability and antioxidant defense systems of algae and the weight change rate, antioxidant defense systems and the DNA damage of earthworms from the view of individual and cellular level. The study not only enrich the data on algae and earthworms, but also provide the scientific basis for the ecological risk assessment and decision support for the management of the pollutants. The results are listed below point by point:1. After exposure to PFOS for96h, the content of the green fluorescence which shows the production of ROS in algae increased with the concentration of PFOS. The production of ROS in the treatment group were all higher than that of control and it also increased with the PFOS concentration.2. The changes of SOD and CAT activity were approximately the same, which appeared to be elevated exposed to the lower concentration first and the decreased with the PFOS concentration. The changes of contents of MDA and ROS showed the same trend. The MDA content of the algae exposed to PFOS were all higher than that of control. The high concentrations of PFOS (120,160, and20mg/L) significantly enhanced the MDA content. The results showed that the stress reaction occurs in cells of algae.3. Compared to the control, both of Chla and Chlb concentrations decreased after exposure to PFOS. the Chla concentration in the all PFOS treated algae was highly significant different with that of the control, while Chlb concentrations reduced significantly only in the higher PFOS treatment. The changes of the content of chlorophyll showed the opposite trend with ROS, which might be the results of the destruction of the chlorophyll and the structure of chloroplast4. The cell permeability reduced significantly first and then rised slowly. All treatments in the cell permeability were lower than the control, which might be relative to the restrain of the esterase.5. PFOS may reduce the growth of earthworm, which might be relative to the changes of cell in molecular and physiological level.6. The SOD, POD, CAT and GSH-Px activities were detected in this paper. The results showed that the activities of the enzymes were initially activated and then inhibited in general.7. The GSH content were markedly depleted, while MDA content were elevated over the duration of the exposure, which suggested that PFOS induced oxidative stress in earthworms.8. The values of olive tail moment, tail DNA%and tail length using SCGE showed similar frequency distributions and increased with increases in the PFOS concentration. These results suggest that all concentrations of PFOS cause DNA damage.