Anthropogenic and geogenic mass input of trace elements to moss and natural surface soil in Norway

Data sets for concentrations of up to 22 elements including Pb, Cd, Ag, As, and Hg and several rare earth elements (REEs) in moss and surface soil from all over mainland Norway are analyzed by positive matrix factorization (PMF) and principal component analysis (PCA) with centered log-ratio transformation. Moss and soil samples collected in 2010 and 2005, respectively, show both a distinct long-range atmospheric transport PMF factor including a dominant Pb loading along with smaller loadings of Mo, Cd, Sb, and As, and a geogenic factor dominated by Ce, La, and Y. Other PMF factors for moss and soil are mainly anthropogenic except for two soil factors, a Cr, Co, Ce dominated factor, and an Eu factor. The source area of Eu is mainly inland consistent with its divalent oxidation state. A significant advantage of PMF factors is that their loadings are scaled according to their relative factor contributions. The PMF air pollution factor F3 in moss with average contribution of 7.11μg/g produces an air pollution input of 5.0μg/g which compares well with literature values for the total Pb concentration in moss for 2005 in southern Norway. PCA has the advantage that it can separate factors with very low element concentrations. To support sources of elements identified by PCA it is recommended to include calculation of factor scores to identify significant source areas.