Monitoring Airborne Heavy Metal Using Mosses in the City of Xuzhou, China

The concentrations of six elements (Cd, Cr, Cu, Ni, Pb and Zn) were measured in moss (Haplocladium microphyllum) samples collected from 55 urban sites in the summer of 2013. The objectives were to evaluate variations in the heavy metal concentrations in mosses across Xuzhou, and to develop maps of metal pollution for this region. Despite great variations in the concentrations of the six heavy metals in the mosses, significant correlations among certain heavy metals were identified, suggesting that these pollutants likely originated from identical sources. With the exception of Cr, there was no significant correlation in metal concentration between the moss tissues and adhering soils. The highest concentration of Cr occurred in the west. However, the spatial distribution for the other metals generally showed higher concentrations in the northeast, likely due to greater contamination by industrial activities and higher traffic volume.