Level of heavy metals in some edible marine fishes of mangrove dominated tropical estuarine areas of Hooghly River, north east coast of Bay of Bengal, India

Abstract

The muscles of some important marine fishes collected in and around Hooghly estuarine coastal areas were analyzed for the heavy metals Cu, Zn, Ni, Cd, Cr and Pb. The concentration range of Cu (16.22-47.97 ppm), Pb (12.40-19.96 ppm) and Zn (12.13-44.74 ppm) were recorded comparatively higher and were similar to that found in contaminated areas. On the other hand the ranges of Ni (2.20-3.69 ppm), Cr (0-3.89 ppm) and Cd (0.62-1.20 ppm) were almost equal to those carried out over a wide range of geographical areas. The degree of bioaccumulations was metal-specific as well as species-specific in nature. The toxic groups of metals (Pb and Cd) showed higher variability than the essential metals (Cu, Zn and Ni). The calculated intake value of metals (week⁻¹ kg⁻¹ body wt) varied from 14.88 to 27.60 of Pb, 0.87 to 1.68 of Cd, 0.0 to 5.45 of Cr, 22.70 to 137.16 of Cu, 3.08 to 5.17 of Ni and 16.98 to 62.60 of Zn through human consumption of these fishes and were compared with those of standard Provisional Tolerable Weekly Intake value (PTWI) per kg body weight as stipulated by WHO. The PTWI(Cal) values of Pb in some of the fishes recorded marginally excess values and may indicate a health risk through consumption of successive 7 days in a week.