Differential toxic response of Chironomus travalensis kieffer ( Chironomidae : Diptera ) to some industrial effluents

Acute toxicity testing of some industrial effluents (rubber (Rr), brewery (Br), and bottling (Bt)) on Chironomus travalensis (Diptera larvae) was determined at 96-h using a static bioassay technique. Effluent quality characterization revealed acidic pH values of 4.5 for Rr, 5.64 for Br, and 4.32 for Bt effluents. Tests were carried out in replicates between 10 and 100% effluent concentrations. Mortality rate rose progressively with increasing concentrations. Bt effluent was the most toxic with 96-h LC₅₀ of 61.5%, closely followed by Rr effluent with 96-h LC₅₀ of 87% and the least toxic was Br effluent with 96-h LC₅₀ of 90%.