Bioaccumulation and regional distribution of trace metals in fish of the Tibetan Plateau

Abstract

There are limited data on trace metals in the fishes of the Tibetan Plateau. In this study, 62 fish samples were collected from six alpine lakes and a river to investigate the levels and spatial variations of trace metals across the Tibetan Plateau. The concentrations of nine trace elements in fish samples were measured using an inductively coupled plasma mass spectrometer after microwave digestion. Results showed the metal concentrations in the fish muscles had the following ranges: Cr 0.09-0.74 mg/kg, Mn 0.38-4.49 mg/kg, Ni 0.06-0.91 mg/kg, Cu 1.00-32.2 mg/kg, Zn 13.1-102.5 mg/kg, As 0.12-3.10 mg/kg, Pb 0.46-3.22 mg/kg, Ba 0.60-4.93 mg/kg, and Se 0.77-9.38 mg/kg on a dry weight basis, respectively. All the lake-averaged metal concentrations in the fish muscle were below the maximum permissible levels set by the Chinese food health criterion (GB2762-2012). The results were analyzed by multivariate statistical techniques to identify the major factors explaining the variance of metal concentrations in the alpine lakes. This work provides baseline data on metal pollution in common fish species of the Tibetan Plateau, contributing to the effective evaluation of both the environmental quality and health status of organisms in the aquatic ecosystem.