FISH UPTAKE AND LEVELS OF Cr, Cu, Cd, Ni, Pb AND Zn IN BEIRE LAKE WATER

Abstract

Fish is considered as a source of protein, carbohydrates, fats, vitamins and minerals to human.Much of the fish available in the Sri Lankan market is harvested from sea. Considerable amountof fresh water fish farming is done in stagnant inland water bodies. Unlike in moving waterbodies, fish and the plants grown in these stagnant water bodies are exposed to pollutants, whichare accumulated over a period. In general, stagnant water bodies in dry zone are contaminatedwith agrochemicals due to poor agricultural practices and the wet zone stagnant water bodies arepolluted due to urbanization and industrialization.

Beire Lake, in Colombo, is the recipient of both the domestic and industrial waste. These inputshave added a considerable burden to the water quality and it is regarded as the most pollutedinland water body in Sri Lanka. The extent of pollution in the Beire Lake is indicated from theeutrophication, dark colored surface water and sediments along with the smell of rotten eggs.Yet, the Beire Lake is used for many human activities such as bathing, washing, recreation andfish harvesting.

This study was undertaken to investigate the levels of Cr, Cu, Cd, Ni, Pb and Zn in the BeireLake water and the levels of fish intake. The sampling and the analysis of these metals werecarried out during the period of 2000-2001. The atomic absorption spectrophotometeic analysisrevealed significantly high levels of these metals in lake water than standards prescribed forportable water. The levels of these metals present in fish were found to be in ppm range, whichcan impose considerable health risk for the consumers.