Acute toxicity of Azadirachta indica (neem) leaf aqueous extract was tested on chickens; and the median lethal dose (LD50) was calculated. Both clinical signs, gross lesion and microscopic lesions at post mortem were recorded.
The indiscriminate discharge of the wastewater generated during the processing of Manihot esculenta Crantz into the environment or public sewers remains a source of concern. In this study, the acute toxicity (96-h LC50) of cassava effluent was evaluated using Clarias gariepinus juveniles and Egera radiata. The two organisms were exposed to different concentrations of the effluent using a renewable static bioassay with continuous aeration. The LC50 of exposed C. gariepinus juveniles was found to be 1.92 ml/L with lower and upper confidence limits of 1.35 ml/L and 2.19 ml/L, while that of E.
The piscicidal potential of water-extract mesocarp of Azardirachta indica was investigated in static biossay experiment with continuous aeration to determine its acute toxicity. The 96-hLC50 was 97.42mg/l while the threshold value was 31.12mg/l. The extract led to an initial increase in opercula ventilation rates which then decreased significantly. The computed regression equation (y) = 4.624 + 6.352 Logc. (r=0.72) and the fish exhibited respiratory distress, loss of balance and erratic swimming prior to mortality. The usefulness of A. indica as piscicidal plant is discussed.
