Moss Biomonitoring of Atmospheric Trace Element Pollution in the Republic of Moldova

The moss biomonitoring technique was used for the assessment of air pollution in the Republic of Moldova, in the framework of the UNECE ICP Vegetation Programme. The content of 11 chemical elements (Al, V, Cr, Fe, Ni, Zn, As, Sb, Cd, Cu, and Pb) was determined by neutron activation analysis and atomic absorption spectrometry in samples collected in spring 2020. Distribution maps were built to identify the most polluted sites. The highest concentrations of elements in mosses were determined in the north-eastern, central, and western parts of the country. The main element associations were identified using factor analysis. Three factors were determined, of which one of mixed geogenic-anthropogenic origin and two of anthropogenic origin. A comparison of the data obtained in 2020 and 2015 showed a significant decrease in the concentrations of Cr, As, Sb, Cd, Pb, and Cu in 2020. The state of the environment was assessed using Contamination Factor and Pollution Load Index values, which characterized it as unpolluted to moderately polluted. Possible air pollution sources in the Republic of Moldova are resuspension of soil particles, agricultural practices, vehicles, industry, and thermal power plants.