A historical record of trace metal deposition in northeastern Qinghai-Tibetan Plateau for the last two centuries.

Shanying Li,Weiwei Sun,Zhenyu Ni,Dongliang Ning,Zhijie Zhang,Rong Chen

doi:10.1007/s11356-021-17618-9

Abstract

Owing to rapid socio-economic development in China, trace metal emissions have increased and lakes even in remote areas have experienced marked changes in the last century. However, there are limited studies revealing long-term trends, anthropogenic fluxes, and spatial characteristics of trace metals in lakes. In this study, we present a geochemical record from Lake Qinghai in the northeastern Qinghai-Tibetan Plateau and reconstruct trace metal pollution history during the last two centuries. The lacustrine sediment core was dated by 137Cs and 210Pb, and sediments deposited prior to the 1850s were selected as the pre-industrial background. Factor analysis and enrichment factor indicated Cr, Cu, and Ni generally originated from natural sources, while Cd, Pb, and Zn have been influenced by human contamination since the mid-1980s. The anthropogenic Cd mainly derived from non-ferrous metal smelting in Gansu Province, and fluxes to Lake Qinghai sharply increased after the mid-1980s. The metal reconstruction is similar to other lake sediment records from China and corresponds well with rapid economic development in China. The spatial pattern of anthropogenic Cd fluxes to lakes is primarily attributed to regional industrial emission, phosphate fertilizers, and manure applied in agriculture.

Highlights

Aquatic ecosystems are habitats of great human importance as they provide essential water resource, help maintain biodiversity and regional ecosystem balance, as well as providing food (Brönmark &Hansson 2002, Ricciardi &Rasmussen 2001)
We present a geochemical record from Lake Qinghai in the northeastern QinghaiTibetan Plateau and reconstruct trace metal pollution history during the last two centuries
Factor analysis and enrichment factor indicated Cr, Cu and Ni generally originated from natural sources, while Cd, Pb and Zn have been influenced by human contamination since the mid-1980s

Summary

Introduction

Aquatic ecosystems are habitats of great human importance as they provide essential water resource, help maintain biodiversity and regional ecosystem balance, as well as providing food (Brönmark &Hansson 2002, Ricciardi &Rasmussen 2001). In spite of their fundamental importance to humans, aquatic ecosystems have experienced unprecedented changes with rapid urbanization and industrialization, such as eutrophication and trace metal pollution, which have led to serious negative effects on the structure and function of these ecosystems (Dudgeon et al 2006, Vanmaercke et al 2015, Liu et al 2013). It is necessary to consider the abundance, transport and persistence of trace metals as well as the effects of anthropogenic activities in the sediments

Objectives

Methods

Results

Conclusion