Turn of the Worms: Assessment of Bavistin FL® (Active Ingredient -Carbendazim) Toxicity in Earthworm, Eisenia andrei under Tropical Conditions.

Abstract

The habitat functions of soils are often assessed by earthworm toxicity tests ISO 11268- 1 and ISO 11268- 2. The sensitivity of these tests is found to be definite but they are labor intensive and time consuming. As an alternative, an avoidance test has been proposed in this paper as a rapid toxicity assessment of pollutants based on the behavioral responses of earthworms. In the present study, avoidance tests have been performed with earthworm species Eisenia andrei with frequently used fungicide, Bavistin FL® (active ingredient - carbendazim) in two different soil types (OECD artificial soil and Natural soil) according to guidelines ISO/DIS 17512-1. Earthworms (n = 10, 4 replicates) in two chamber systems were exposed to a series of carbendazim concentrations ( l, 3, l 0, 30, l 00, 300, 900 mg a.i / Kg dry soil) together with controls and kept for 48 hat 28 ± 2 c0 Some dual control tests . were performed to ensure the random distribution of the worms and the net response was calculated as the end point. In these tests, no significant difference (p > 0.05) was found in two untreated sides of the controls. The results indicated significant avoidance behavior of earthworms even in low concentrations. The EC50 value of 34.3 mg a.i / Kg dry soil for natural soil and 126.4 mg a.i / Kg dry soil for OECD soil indicates that Bavistin FL® is more toxic in natural soil than OECD soil. These results also indicate that the sensitivity of Eisenia andrei in tl}e avoidance test is high