Biomonitoring techniques for testing the pollution impact of Recovered Derived Fuels (RDFs): a ten-year-long study case centred on a cement mill in NE Italy
(1) Dipartimento di Scienze della Vita, Università di Trieste, Via L. Giorgieri 10, I-34127 Trieste, Italy, (2) Dipartimento di Ingegneria e Architettura, Università di Trieste, Via A. Valerio 6/1, I-34127 Trieste, Italy
Recovered Derived Fuels (RDFs) can be burned for thermal recovery as a valid alternative to conventional fossil fuels, reducing landfill disposal of non-recyclable plastics. RDFs are increasingly used by industry following an authorization process that imposes specific emission controls and limits that are typically more stringent than those applicable to other fuels. The potential dispersion of persistent organic pollutants (POPs) and potentially toxic elements (PTE) into the environment resulting from imperfect combustion of RDFs remains, however, one of the major public concerns limiting much greater use of RDFs. Therefore, proper assessment of total POPs and PTEs load in an area and the identification of past vs. current emission sources are critical to making RDFs use a common practice on an industrial scale. Here we describe the results of a multi-organism biomonitoring plan, conducted between 2012 and 2023 around a cement factory that had been in operation since 1950, received approval to use RDFs as a co-fuel in 2014, and became fully operational in 2017. Ante- (2012) and post- (2018, 2023) operam surveys were organized with winter and summer campaigns, based on active biomonitoring of POPs and PTEs at 40 sampling sites systematically distributed over an area of 40 km2 in the typical mixed land use of NE Italy, with a lichen [Pseudevernia furfuracea (L.) Zopf] and a tree (Robinia pseudoacacia L.) as target organisms. Thanks to the high sampling density, a spatial relationship between pollutant concentration in target organisms and sampling site distance from the cement factory was ruled out, while other putative sources were associated to specific pollutant categories: for PTEs, an industrial park; for PCBs, three individual hot-spots interested by past spill-overs; for PAHs, traffic and domestic heating. Overall, the current use of RDFs by the cement plant has a negligible impact on the total environmental perturbation caused by human activities in the area.
Keywords: Air Pollution, Lichen Transplants, Recovered Derived Fuels, PAH, POP, PTE
