Heavy Metal Levels in Food Fish, Etroplus suratensis Inhabiting Bolgoda Lake, Sri Lanka

Abstract

Bolgoda Lake is used by the local community for traditional fishery. Nevertheless it is becoming polluted with chemicals from various sources. The present study was carried out to assess the total levels of five heavy metals viz lead, cadmium, chromium, copper and zinc in the muscle, gill and liver tissues of Etroplus suratensis, a food fish inhabiting Bolgoda Lake. Fish samples were collected from four main locations of the Lake viz. Weras Ganga, North Lake, Bolgoda Ganga and South Lake and metal levels were determined by atomic absorption spectrometry. Total metal levels in muscle tissue (in ug g' wet weight) of the fish collected from Bolgoda Lake showed a wide range: lead, 0.02- 20.1, cadmium, 0.01 - 0.3, chromium, 0.01-0.2, copper, 0.1 - 10.1, and zinc, 2.5-10.4 (n=60). Of the different metal levels detected in the edible muscle of the fish, the level ofPb in 100% of the fish sampled from Weras Ganga, 87% of the fish from Bolgoda Ganga and 13% of the fish from North Lake and the level of Cd in 13% of the fish from Weras Ganga and Bolgoda Ganga exceeded the maximum levels in food for human consumption specified by European Union. Comparison of the metal levels in the muscle, gills and liver tissues indicated that the highest accumulation of metals occurred in the liver tissue of the fish. The results indicate that heavy consumption ofE. suratensis from Bolgoda Lake especially from Weras Ganga and Bolgoda Ganga may pose a health risk to the consumers.