Abstract
An acute toxicity test for first-instar chironomid larvae was improved by using a Teflon sheet to prevent larvae from being trapped at the water surface during a 48-h test period. The improved procedure ensured that OECD test guideline 202 would be applicable for chironomids. Using the improved procedure, we performed several acute toxicity tests for metals, resulting in 48 h LC50 (95% C.I.) were 0.53 (0.45-0.64) and 0.93 (0.74-1.2) mg/L for CdCl2 and CdSO4, respectively, versus 0.10 (0.09-0.11) and 0.12 (0.09-0.14) mg/L for CuCl2 and CuSO4, respectively.
