Spatial Distribution and Ecological Risk Assessment of Potentially Harmful Trace Elements in Surface Sediments from Lake Dali, North China

Min Xu,Weiwei Sun,Rong Wang

doi:10.3390/w11122544

Abstract

Potentially harmful trace element (PHTE) pollution in lakes has important implications for regional management in North China, yet is seldom investigated. Surface sediments from 13 sites in Lake Dali were collected for PHTE analysis. Combined with the enrichment factor, potential ecological risk index, and multivariate statistical analysis, the spatial distribution and ecological risk of the pollutants were studied. The results showed that the contamination levels of As, Cd, Cr, Cu, Ni, Pb, and Zn were minor to moderate. Cd, Cr, Cu, Ni, Zn, and part of Pb pollution were mainly attributed to atmospheric deposition with the development of industry in North China, and As pollution resulted from the agricultural use of chemical fertilizers and As-containing pesticides. For the overall lake, the southwest part requires the most management, and targeted measures should be tailored to mitigate the ecological risk of PHTE pollution.

Highlights

Lakes are vitally important ecosystems, providing many social and ecological functions such as regional water supply, biodiversity preservation, and climate regulation
Lake Dali were all higher than their corresponding background values; the values of Cr, Cu, Ni, and Zn in some sites were lower than their background values [29]
China and abroad (Table 1), we found the concentrations of potentially harmful trace element (PHTE) in Lake Dali were much lower than in the lakes in the Eastern Plain and Yunnan–Guizhou Plateau, but they were close to those of lakes in the Mongolia–Xinjiang Plateau and the Songnen Plain and in other countries [1,6,10,12,19,20,21]

Summary

Introduction

Lakes are vitally important ecosystems, providing many social and ecological functions such as regional water supply, biodiversity preservation, and climate regulation. With increasing industrialization in recent decades, many lakes in China are at risk of potentially harmful trace element (PHTE) pollution [1,2,3]. PHTEs primarily adsorb and accumulate on the sediments; lake sediments can provide records for understanding the history and consequential risk of PHTE contamination [4,5]. Characterized by high toxicity, long persistence, and biological accumulation, the PHTE pollution of lake sediments has attracted increasing attention [6,7]. Studies have mainly concentrated on large lakes in populated areas, such as the lower Yangtze River Basin and Southwest China, which reported that PHTE pollution is increasing serious in these lakes [10,11,12].

Methods

Results

Discussion

Conclusion