Moss Bag Biomonitoring of Airborne Pollutants as an Ecosustainable Tool for Air Protection Management: Urban and Agricultural Scenario

Urban and agricultural areas are highly anthropogenically devastated environments with diversely and densely distributed pollution sources. These usually highly populated and cultivated areas together represent a big part of the Earth’s surface, and it is of crucial interest to monitor and control presumably high air pollution in these areas. Complex urban topography demands a high density of air quality monitoring stations while extensive and frequent agrochemical treatments in cultivated areas require repetitive measurements of pollution at the same site. The application of moss bags represents an easy-to-apply screening technique which has been used for biomonitoring of air pollutants. The technique has been mainly developed for application in areas where the naturally growing biomonitors are absent. It is successfully used for biomonitoring of potentially toxic elements including rare earth elements (PTEs) and persistent organic compounds, mostly polycyclic aromatic hydrocarbons (PAHs). In the last decade, we investigated crucial variables of the moss bag technique application (species-specific, time- and site-dependent pollutant enrichment) through a series of studies performed in the urban area of Belgrade and agricultural areas in Serbia. Starting from 2005, we have examined the moss bag technique for biomonitoring of PTEs at specifically polluted sites within the city such as crossroads, street canyons, tunnel and garages and, finally, overall city area. Thereafter, since 2015, we tested the technique application in conventional and organic vineyards. The interchangeable use of two moss species, Sphagnum girgensohnii (a species of the most recommended biomonitoring genus) and Hypnum cupressiforme (commonly available in Serbia), for performing the biomonitoring of PTEs was discussed in the studies. The results showed that the studied moss species could not be interchangeably used for airborne element assessment, except for Cr, Cu and Sb. In the urban area, 2-month bag exposure ensures accumulation of the elements and adequate replicability of the results even at air pollution background sites. Otherwise, in the agricultural area, this period does not guarantee detectable element moss load if the bag exposure does not coincide with the agrochemical application time (which is variable in different vineyards). Hence, in a vineyard ambient, moss bags should be exposed during the whole grapevine season comprising unpredictable treatments of grapevine during the vegetation season. The moss bag technique enables uniformly biomonitoring of the air pollutants over all anthropogenically devastated areas since successfully overcomes the issue of lack naturally growing mosses.