Field application of humic acid against the effect of cadmium pollution on cultured tilapia Oreochromis niloticus.

Abstract

The role of humic acid in protecting Oreochromis niloticus from the harmful effects of cadmium exposure was studied. The exposure of fish to 15 ppm cadmium increased the concentration of cadmium in liver, kidney, musculature and gills. Cadmium exposure significantly decreased the red blood cells count, hemoglobin concentration, packed cell volume (PCV), total protein, albumin, globulin concentrations increased. The cadmium exposure increased also lipid peroxidation, reduced glutathione concentration in the liver, kidney, musculature and gills. The fish were treated with 15, 30 and 50 mg/l of humic acid through the pond water during cadmium exposure. The concentration of 15 mg/l had no significant effect on the cadmium exposed fish while the treatment of fish with 30 and 50 mg/l humic acid significantly reversed the effects of the cadmium toxicity. Key word: Humic acid Cadmium -Oreochromis niloticus Lipid peroxidation Reduced glutathione