Air quality biomonitoring in an urban and industrial hot-spot of Central Italy

Over the last decades, various scientific studies had underlined the potential of biomonitoring to assess environmental quality. The utilization of organisms as bioindicators have been widely described. Biomonitoring often results to be a low-cost and efficient method for the evaluation of environmental quality in comparison to the definition of a traditional monitoring network. In this study we describe the application of two biomonitoring approaches to assess the air quality of Terni (Central Italy). This city is an urban and industrial hot-spot situated in an intramountain depression characterized by the presence of several atmospheric particulate matter (PM) anthropogenic emission sources. Peculiar meteorological and geomorphological conditions of Terni basin limit the dispersion and enhance the accumulation of atmospheric pollutants. Firstly, we described the application of lichens transplants as bioindicators of air pollution. Lichens proved to be efficient and low-cost bioccumulators of airborne elements considered tracers of anthropogenic emission sources. In fact, these organisms are characterized by a lack of wax cuticle that allows the adsorption of airborne contaminants in their tissues. Lichens trasplants are easy to collect, easily available and they allow the construction of dense, extended and very low-cost monitoring network. 23 lichens transplants (E. prunasti) were located at different collection sites along with new and innovative PM samplers to compare the obtained results and validate their efficiency. Secondly, PM deposition analysis were conducted on A. donax leaves, a widely distributed riparian species. Leaves were collected along the river that cross the basin (Nera river) near the main emission sources. Washed and unwashed leaves were chemically analyzed to evaluate the contribution of the deposition of anthropogenic PM, along with water and soil samples collected in the same sites. Lichen transplants appeared to be good biomonitors for air quality, especially for the emission evaluation of elements at high concentration (such as Nickel and Copper emitted by the steel plant and vehicular traffic present in the area). Finally, results obtained from the chemical analysis of A. donax leaves allowed us to assess the particulate matter deposition and to discriminate the impact of the emission sources across Terni basin.