| Heavy metal (Cr, Fe, Cu, Zn, As, Cd and Pb) concentrations were measured in 17 moss samples which were collected at Qiyi Glacier Region in July, August and September, 2009 in a preliminary investigation of heavy metal pollution situation in this area. The results indicated that heavy metal concentrations in mosses were relatively high and concentrations of Fe were at the highest level (varied between 15160.00 and 34960.00 μg·g-1), followed by Zn, Cu, Cr, Pb, As, with average concentrations of 169.56, 134.81, 34.52, 26.16, 9.15 μg·g-1. Enrichment factor analysis and correlation analysis indicated that Fe and Cr in mosses mainly stemmed from crustal dust, and concentrations of Cu, Pb, Zn and Cd were influenced by human activities; As was moderately enriched which means As in mosses was mainly originated from anthropogenic pollution. According to the Global Data Assimilation System (GDAS) meteorological data from the National Center for Environmental Prediction (NCEP) of 2009 and the simulation of the HYSPLIT v4.9 Model on 3-dimension back trajectories of air mass at Qiyi glacier district, several trajectories reflecting the main characteristics of air flow were obtained based on the classification of cluster analysis on the hundreds of back trajectories. The back trajectories revealed that atmospheric transport characteristics in the study area changed obviously by season. Compared to Spring and Autumn, atmospheric transmission sources were relatively more in Winter and Summer. The main sources of atmospheric pollutants in Qiyi Glacier region were transported from Jiuquan and Jiayuguan regions. |
