Assessment of potentially toxic heavy metals and health risk in water, sediments, and different fish species of River Kabul, Pakistan

ABSTRACT

Contamination of freshwater bodies and consequently freshwater fish with toxic heavy metals is a serious environmental issue. The trophic transfer of potentially toxic heavy metals in the human food chains, especially in fish has important implications for human health. The present research study was designed to assess the concentrations of the heavy metals Cr, Ni, Cd, and Pb in the water, sediments, and different freshwater fish species of River Kabul, Pakistan. The heavy metals were quantified in the samples with Atomic Absorption Spectrophotometer. Heavy metal contamination in fish muscles was characterized in terms of metal pollution index and biota-sediments accumulation factor, while human health risk was assessed through calculation of estimated weekly intake. The average concentrations of Cr, Ni, Cd, and Pb in muscle samples of the analyzed fish species at different sampling sites of the river ranged from 12.3 to 33.0, 33.2 to 109.2, 0.98 to 1.5, and 13.9 to 29.6 mg kg⁻¹ wet weight, respectively. Based on the current study data, consumption of the analyzed freshwater fish species from River Kabul was generally safe in terms of potential risk from Cd and Pb but the observed Ni accumulation may pose a potential health risk to regular/excessive fish consumers.

KEYWORDS:

• bioaccumulation
• freshwater fish
• heavy metals
• Pakistan
• risk assessment
• River Kabul

Acknowledgments

The authors are thankful to Mr. Ashfaq Ahmad, Mr. Tauseef Ahmad and the local fishermen for their help in fish collection. Cooperation of Dr. Muhammad Anwar Sajad, Department of Botany, Islamia College Peshawar, in heavy metal analysis is also gratefully acknowledged.