Evaluation of the suitability of Tillandsia usneoides as biomonitor of airborne elements in a natural environment of Italy
(1) Department of Agriculture, Food and Environment, University of Pisa, Via del Borghetto 80, 56124 Pisa, Italy; (2) BI-Lab Research for Environment, Via dell’Unione 30, 00053 Civitavecchia (RM)
The suitability of a rootless Bromeliad species (Tillandsia usneoides L.) as biomonitor of airborne trace elements in suburban/urban areas of the Mediterranean basin was evaluated. The study was performed in nine sites of the Pollino National Park (Cosenza and Potenza provinces, Southern Italy) differing for land use, anthropogenic activities and/or proximity to emission sources, mainly a biomass power plant. Fluoride and sulphur were investigated, as the most emitted pollutants. Unwashed and washed samples, collected after 90 days of exposure (May - August 2023), were analysed by ICP-MS. Results showed significant differences among sampling sites for both elements suggesting that in our local monitoring network a clear location-specific differentiation of pollutant levels occurred, strictly related to potential emission sources. Concentrations of fluoride were higher in urban/traffic and/or suburban/traffic areas. In the industrial site, sulphur levels were much higher than in rural/remote areas (+70%). The results indicated that T. usneoides reflects the intrinsic characteristics of each sampling area and allows tracing back differences related to the various emission sources by factor analysis. In particular, T. usneoides showed: high resistance/tolerance to heavy metal toxicity, specificity, capability to well-definitely represent a sampling site, quantitative response to pollutant exposure.
Keywords: Biomonitoring, rootless plant, pollutants, heavy metal toxicity
