Biomonitoring trace element contamination impacted by atmospheric deposition in China's remote mountains

Abstract

The purpose of this study is to better understand the key driving factors affecting the distribution of trace elements in remote mountainous areas at a national scale. In this regard, eight trace elements (As, Cd, Cr, Cu, Ni, Pb, Sb, Zn) in mosses were investigated at thirty remote mountains across China. The sources and possible factors controlling the distribution of trace elements in the mosses were identified through multivariate statistical analysis and Pb isotopic ratios. The results showed that the concentrations of trace elements in the mosses were higher than the levels in most European countries but comparable to those in Chinese cities. Mosses had the highest concentration levels of Cd and Sb and slightly lower levels of other trace elements. Spatially, moss contamination with the trace elements was significantly higher in the eastern, southern and southwestern China than in other regions. Mining-related activities, fuel combustion and other industrial emissions were identified as the main anthropogenic sources of As, Cd, Pb, Sb and Zn, whereas Cr, Cu and Ni were mainly from natural sources. The precipitation from monsoons clearly altered the distribution of anthropogenic elements in the mosses. The results of this study indicate that the trace elements in the mosses of China's remote mountains were affected by regional anthropogenic emissions, and the monsoon-dominated trace element transport and deposition should be highlighted at a large regional scale. These findings provide baseline data for future targeting policies to protect remote ecosystems from long-term inputs of trace elements via long-range atmospheric transportation.