Heavy metal accumulation in woodland moss (Pleurozium schreberi) in the area around a chromium opencast mine at Kemi, and in the area around the ferrochrome and stainless steel works at Tornio, Northern Finland

Woodland moss (Pleurozium schreberi) samples were collected at 52 sampling sites around a chromium opencast mine and around a ferrochrome and stainless steels works. The samples were dried, homogenized and digested with a mixture of concentrated nitric and perchloric acids. The Cr, Ni and Zn concentrations in the moss samples were determined by FAAS in order to clarify the aerial distribution of heavy metals from both the opencast chromium mine and the ferrochrome and stainless steel works. This study, carried out in 2000, compares the heavy metal (Cr, Ni, Zn) concentrations in mosses to the results of previous studies in 1995 and in 1990. According to the results, the average Ni concentrations (mean) in mosses have increased since 1990 along with increased Ni emissions from point sources, but the average Cr concentrations (mean) in mosses have increased despite the decrease in Cr emissions from point sources have decreased. The results have been discussed from various point of view, as well as depicted out the low deposition of Zn on mosses.