[Acute toxicity and bio-concentration factor of three pesticides on Brachydanio rerio]

The acute toxicity and bio-concentration factor of imidacloprid, triazophos and pyridaben were measured by using Brachydanio rerio as test organism. The 96 h LC50 value of these pesticides was 281.37 mg x L(-1), 8.37 mg x L(-1) and 11.66 microg x L(-1), respectively. The concentrations of pesticides and the exposure duration of 14 days for BCF tests were designed according to results of the acute toxicity tests and relevant guideline. At the exposure concentrations of 0.5 and 5 mg x L(-1), the bio-concentration factor (BCF) of imidacloprid was 1.52 and 0.97, respectively; while at the exposure concentrations of 0.02 and 0.2 mg x L(-1), that of triazophos was 9.00 and 8.45, respectively. For pyridaben, the BCF was respectively 5600 and 4920 at the exposure concentrations of 0.1 and 1 microg x L(-1).