Vol. 3, Issue 1, Part G (2017)

Abstract
The present study was conducted to determine heavy metal concentrations in various tissues of gills, liver and muscle from the selected fresh water fish Oreochromis mossambicus. The fishes were exposed to sub lethal concentrations of lead acetate for 96 hr and LC₅₀value was found to be 18.7ppm. One -tenth of (1/10) LC₅₀ (1.87 ppm) value was selected as lower sub lethal concentration for a period of 30 days. The fish organs viz., gills, liver and muscle from the selected fresh water fish was carefully dissected for determination of heavy metal using ELICO’s SL – 176 double beam Atomic Absorption Spectrophotometer (AAS). The results revealed that the presence of even (1.87 ppm) low concentration of lead accumulation exhibits a maximum level in liver (0.720 ± 0.0027 µg/g), gills (0.611 ± 0.0036 µg/g) and muscle (0.249 ± 0.0041 µg/g) tissues of 30 day exposed fish. The result of the present investigation reveal a time dependent lead accumulation in the different tissues of fishes exposed to different periods of sub-lethal concentration of lead. These findings extend for future studies on the evaluation of lead accumulation tendency in relation to the ecotoxicological examining programme for risk assessment.