Assessment of Toxic Elements in Atmospheric Deposition in Azerbaijan Using Moss Biomonitoring Methods

This study investigated atmospheric heavy metal deposition across three western regions of Azerbaijan - Goygol, Gadabay, and Dashkasan - within the framework of the UNECE International Cooperative Programme on Effects of Air Pollution on Natural Vegetation and Crops (ICP Vegetation), employing moss biomonitoring as the primary investigative approach. Two dominant moss species, Hylocomium splendens and Pleurozium schreberi, were collected and analysed for a total of 44 elements using a combination of neutron activation analysis (NAA), atomic absorption spectroscopy (AAS), and particle-induced X-ray emission (PIXE). Interelemental relationships were examined through factor analysis, which yielded four distinct factors representing major source groups. When Azerbaijani moss data were compared against Norwegian reference values, elevated concentrations of most heavy metals - including Mg, Al, V, Fe, As, Mo, Cd, La, and U - were recorded in the sampled material. Mosses were utilised as passive bioindicators to quantify elemental pollutant loads in atmospheric deposits and characterise the general pollution status of each study area. Geospatial distribution maps were generated to delineate the most heavily polluted zones and establish links to known contamination sources. Elemental concentrations in mosses collected from Dashkasan and Gadabay were found to substantially exceed those measured in Goygol samples, reflecting the stronger anthropogenic influence in the former regions. In addition to industrial and agricultural pressures, local geological characteristics - specifically lithology and soil composition - were identified as contributing factors governing spatial variability in elemental distribution.