DETERMINATION OF LC50 AND EC50 FROM ENDOSULFAN LACTONE AND DIAZINON IN EARTHWORM (Eisenia foetida)

Abstract

This study evaluates acute toxicity as the mean lethal concentration (LC50) and the mean effective concentration
(EC50) of endosulfan lactone and diazinon in Eisenia foetida earthworm, as well as its visible physiological effects. The
methodology followed was established by the OECD (207) using the techniques of filter paper (FPT) at 48 hours and
artificial substrate (AST) at 14 days, resulting in CL50=7.1 ?g cm^-2 ; 0.60 mg kg^-1 and CE50?9.6 ?g cm^-2; 0.41 mg kg^-1
of endosulfan lactone, in FPT and AST respectively; and CL50=14.9 ?g cm^-2; 139 mg kg^-1 y CE50=11.77 ?g cm^-2; 187
mg kg^-1 of diazinon, in FPT and AST respectively, evaluated by Probit analysis. The main physiological effects on the
worm were growth inhibition, thinning, sectioning, bleeding, upper and lower swelling and death. The results show that
endosulfan lactone is more toxic than diazinon for Eisenia foetida.