Bioaccumulation and potential sources of heavy metal contamination in fish species in River Ganga basin: Possible human health risks evaluation.

D.S Malik,Krishna Kumar Yadav,Pradip Kumar Maurya,Sandeep Kumar,Amit Kumar,Hesam Kamyab

doi:10.1016/j.toxrep.2019.05.012

Abstract

This paper assesses the potential human health risks posed by five heavy metals (Zn, Pb, Cu, Cd, and Cr) found in seven most consumable fish species (Cirrhinus mrigala, Cirrhinus reba, Catla catla, Lebio rohita, Crossocheilus latius, Clupisoma garua, and Mystus tengara) collected from local markets of Varanasi, Allahabad, Mirzapur, and Kanpur of Uttar Pradesh, India. The Cu concentration was found at Varanasi (4.58 mg/l), Allahabad (2.54 mg/l), and Mirzapur (2.54 mg/l). Pb was recorded 0.54, 0.62, 0.85, and 0.24 mg/l at Kanpur, Allahabad, Mirzapur, and Varanasi, respectively. The Cd concentration was recorded 0.54, 0.68, 0.78, and 0.85 mg/l at Kanpur, Allahabad, Mirzapur, and Varanasi, respectively. The Cr, Cd, and Pb concentrations in the river water were observed over the prescribed safe limits at all sampling sites, while Cu concentration was higher than the standards at all sites except Kanpur. However, Zn was observed under the permissible limits (15 mg/l) at all sampling sites. In case of fish tissues, WHO reported the concentration of Pb, Cd, and Cr higher than the prescribed safe limits. The results determined that the highest heavy metals accumulation was found settled in the liver of all selected fish species. Zn ranked the highest quantity, which was found in fish tissues with the concentration of 32.41 ± 2.55 μg/g in the gill of C. catla and 4.77 ± 0.34 μg/g in the gill C. Reba. The metals followed the magnitude order of Zn > Pb > Cu > Cd > Cr in selected fish tissues.

Highlights

IntroductionThe Ganga River (a perennial river originating from Gangotri glaciers), which is one of the major rivers of Ganga-Brahmaputra-Meghna system, contributes > 43% (861,452 km2) of the cumulative catchment area
The Ganga River, which is one of the major rivers of Ganga-Brahmaputra-Meghna system, contributes > 43% (861,452 km2) of the cumulative catchment area
We found that all the selected heavy metals except the Zn were higher than the permissible limits stated by the World Health Organisation (WHO)

Summary

Introduction

The Ganga River (a perennial river originating from Gangotri glaciers), which is one of the major rivers of Ganga-Brahmaputra-Meghna system, contributes > 43% (861,452 km2) of the cumulative catchment area. Especially caused by partially treated and untreated waste, is the major threat to the river biodiversity. Treated and untreated waste is discharged into the river through about 36 Class-I towns and 14 Class-II towns. The existence of heavy metals (Cd, Cr, Cu, Mn, Ni, Pb, and Zn) in the river water has been previously reported [4,5,6,7,8] together with sediments due to inputs of industrial wastes [9,10], sewage effluent [11], agricultural runoff, and domestic wastes [12,13,14]. The pedological processes serve as the sources of pollutants, especially heavy metals that may appear due to the weathering of rocks through surface runoff water [15,16,17]

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