Safety Evaluation Of Pyrethroid To Carp

Based on the acute toxicity of pyrethroid to carp ,the subchronic toxicity and high concentration short-time impact of pyrethroid were studied.The results showed that cycloprothrin and etofenprox and cypermethrin is highly toxic,moderate toxic and highly toxic to carp respectively.High concentration short-time impact examination showed that the impact of pyrethroid on carp is not severe when the case of concentration is not too high and time is not too long, most of the poisoned carp come back after the carp that exposured high concentration cycloprothrin were transferd to fresh water.The subchronic toxicity experiment studied the effects of different pyrethroid concentration (1/10 1/20, 1/40 1/80 of 96hLC50) on the behaviour, growth ,haematological biochemical indices and pathology of carp in 60 days. The results showed that pyrethroid had no effect on the body length while had obvious influence on the body weight intake of food and swiming, some carp then showed intermittence toxic symptom until death.Compared with the control,the effect of pyrethroid on haematological biochemical indices of carp was significant. The Hb concerntration, RBC numbers,TP and AP numbers and the serum sodium level dropped ? The serum ALT and AST activity and serum potassium level raised .These haematological difference of the treated groups were significant(P>0.05) or very significant(P>0.01) compared with the control group.The result of routine tissue dyeing assay showed symptoms of hyperemia, swell, fatty, vacuolar and granular degeneration in the liver cells of treated carp; Hyperemia,swell and vacuolar degeneration in the renal tubular epith epithelial cell and lymph cell inroad; Hyperemia,swell ,hyperplasia and slough in the gill lamella epithelium;Hyperplasia in lymph cell,gill lamella length becomed different and frame foul-up.The influence become severer with the concentration increasing.Advice was given that pyrethroid should be used scientificly, the application concentration of cycloprothrin, etofenprox and cypermethrin of water area should be less than 0.685 mg/L,0.057mg/L and 0.020 ug/L respectively.