Pollution Research Paper

TOXIC METAL CONCENTRATIONS IN FIVE FISH SPECIES AVAILABLE AT CITY MARKET, RAJSHAHI, BANGLADESH

M.R. ZAMAN, R.A. BANU1 AND M.S. ISLAM

Abstract

In this study we have used atomic absorption spectrophotometry (AAS) to determine the concentration of potentially toxic heavy elements viz. As, Pb, Cd and Mn in locally available and highly consumed five fish species collected from central city market (called Shaheb Bazar), Rajshahi, Bangladesh. Sampling was made during the month of February 2006. It is observed that out of five, three fish species (viz. Pangasius pangasius, Labeo rohita and Macrobrachium rogenbergii) are burdened with lead ranging from 13.96-26.54 mg Kg-1 compared to the permissible value of 0-7.2 mg Kg-1 (dry weight basis). Pb concentrations are significantly higher in Pangasius pangasius, Labeo rohita and Macrobrachium rogenbergii but Puntius sarana and Hilsha ilisha fishes show Pb content within the safe limit; Hilsha ilisha records the lowest. The sequence in Pb concentrations according to fish species is in the order of P. pangasius (26.54 mg Kg-1) > L. rohita (19.71 mg Kg-1) > M. rogenbergii (13.96 mg Kg-1) > P. sarana (3.91 mg Kg-1) > H. ilisha (2.63 mg Kg- 1). Results revealed that in terms of As, Cd and Mn, all fish species including P. sarana and H. ilisha are quite safe for human consumption and no public health problem would be raised; however, Pb contents in P. pangasius, L. rohita and and M. rogenbergii exceed the recommended limit. The metal concentrations found in this study were similar to the metal levels of fishes collected from slightly polluted waters all over the world. Present investigation so far is a first attempt to characterize the indigenous fish species available at Rajshahi City area in terms of As, Pb, Cd and Mn. The results might be useful for evaluating health risks resulting from contamination. Results also would provide support towards remediation related decisions.