Determination of Heavy Metal Pollution in Zonguldak (Turkey) by Moss Analysis (Hypnum cupressiforme)

Abstract

This paper explores the first attempt at determining the levels of atmospheric heavy metal contamination in the Zonguldak province through the analysis of moss (Hypnum cupressiforme Hedw.). Sampling was performed at 24 sites after a wet period to avoid contamination from soil compounds in the province. Dried samples, which were unwashed but cleaned of soil particles and other extraneous material, were digested with HNO(3)/HClO(4). Concentrations of heavy metals (Fe, Cu, Pb, Cr, Co, Ni, and As) were analyzed by ICP-OES to estimate the geographic distribution of the atmospheric heavy metal depositions. The general order of the concentrations of the heavy metal content in Hypnum cupressiforme Hedw. was observed to be Fe > Pb > Cu > Ni > Cr > As > Co. Mean levels of the measured elements were higher when compared to European levels. Arsenic, iron, and chromium were the most elevated elements when compared with European data. The mean concentrations of these elements in the studied area were 8.3 (Co), 6.7 (Fe), 5.2 (Cr), 4.6 (As), and 2.7 (Ni) times the background levels of the reference site (C3). Among the studied heavy metals, only lead showed little variation in measured values due to traffic in the area. Main sources of increased heavy metal content of the moss samples were found to be: i) the Catalagzi Power Plant (CATES); ii) the Eregli Iron-Steel Plant (ERDEMIR); iii) space heating; and iv) traffic-related emissions. Results are presented in the form of color-scaled contour maps using a Geographic Information System (GIS)-based mapping technique.