Acute Chronic Toxicity of Lindane in Channa punctatus

In the present study, the response of the fish, C. punctatus, to different concentrations of lindane (0.1, 0.2, 0.3mg l-1) was found to be largely dependent on the concentration of pesticide and period of exposure (24, 48, 72 and 96h). Toxicity testing within 24h shows 40% mortality at 0.3 mg l^-1; within 48h, 60% mortality was observed at 0.3 mgv l^-1 and 20% at 0.2 mg l^-1; within 72h, 40% at 0.2 and 80% at 0.3mg l^-1, respectively. Within 96h, no mortality observed in control, whereas at 0.1, 0.2, and 0.3mg l^-1, the mortality observed was 20, 80 and 100%, respectively. The 96h LC₅₀ value of lindane was calculated by two methods (Finney probit analysis; Dede and Karber), the value being 0.15mg l^-1. The acute chronic ratio calculated was found to be 11.811 in 30 days, 21.45 in 60 days and 30.82 in 90 days respectively at EC10%. Though the ACR values were within the safety guidelines established by REACH, a rising trend was seen. The results showed that lindane was directly impairing the behavioural and physiological processes in fish.

Keywords: Toxicity; LC₅₀; Mortality; Probit; ACR