Molecular Toxicology Of Cypermethrin To Fish

Cypermethrin is one of the synthetic pyrethroid, which is widely used to control insect pests and is found to be more effective than organphosphates and carbamates. However, it is also reported to be more toxic than organphosphates and carbamates. It has been suggested that synthetic pyrethroids are readily absorbed by the gills of fish even at very low concentrations.In this experiment, at first, the effectiveness of beta-cypermethrin on the acute toxicity and on serum GPT and GOT concentration of crucian was studied. The 96hr LC₅₀ of beta-cypermethrin for crucian was 11.4μg/L. The crucian serum was treated against beta-cypermethrin levels of 0.114μg/L, 0.57μg/L and 1.14μg/L for exposure times of 0d, 5d, 10d, 15d and 20d, at all concentrations. The results show that when the beta-cypermethrin concentration increases and the exposure time is prolonged, the GPT and GOT activities of serum increased also. The results proved that beta-cypermethrin could cause great damage to crucian and its biochemical functions.And then in this experiment, the affection of cypermethrin on acute toxicitiy, geno-toxicity and LDH polyacrylamide gel electrophoresis of crucian were studied. The experiment result indicated that the 96hr LC₅₀ of cypermethrin to the crucian is 20.74μg/L. The crucian then was treated at cypermethrin levels (0μg/L, 2μg/L, 5μg/L, 10μg/L) for 4d respectively. The results showed that the micronucleus rate and nuclear anomaly of erythrocytes became high along with concentration raised. And the activities of the kidney lactate dehydrogenase LDH2, LDH3, LDH4 became high, but LDHl and LDH5 kept steady. All of these changes can pointed out that cypermethrin has damage to the organizations of crucian.And acute toxicity experiment of cypermethrin to carp was also carried out. The results showed that the LC₅₀ of cypermethrin in 96hr for carp was 12.6μg/L. And then 35d subacute exposure was conducted to determine the damage of cypermethrin to carp. In sub-acute exposure tests, cypermethrin of 1.14μg/L restrained growth of carp, and of 0.58 and 1.14μg/L it damaged obviously to the gills of carp. It indicated that the most allowable concentration of cypermethrin to carp was 0.28⁰.58μg/L.