Contaminants of Emerging Concern: occurrence and distribution in aquatic environments

The aim of this PhD study was to assess the occurrence, behavior and fate of Contaminants of Emerging Concern, and more specifically Endocrine Disrupting Compounds (EDCs) in natural freshwater and saltwater environments. To this purpose, estrogens, perfluorinated compounds (PFCs) and phenolic compounds were analysed in the freshwater environment of the Romagna area (Italy). Two sampling campaigns were carried out in two following years during summer. Wastewater treatment plant effluents were the main source of introduction of PFCs in the water compartment, whereas phenolic compounds occurrence was likely related to the presence of industrial activities. Both PFCs and phenolic compounds were persistent in the aquatic compartment during the monitoring periods. On the contrary, estrogens occurrence was not constant over time, suggesting local sporadic events of contamination. Sediments were mainly affected by the occurrence of the phenolic group, whose presence was controlled by sediment size and organic carbon content. Analysis on the surrounding transitional environment of the Pialassa Baiona revealed salinity to be a relevant element controlling their partition between water and sediment. PFCs were also analysed in the transitional environment of the Ebro delta (NE Spain) during three sampling campaigns (autumn, winter, spring-summer). PFCs were confirmed to be persistent in the water compartment over the year. On the contrary, concentrations in sediments were highly influenced by seasonality. Nevertheless, a greater partition of PFCs between water and sediment was registered in the Ebro delta, in contrast with their almost absence in riverine sediments of the Romagna area, as a consequence of PFCs lower solubility in saline environments. Analyses of PFCs in both seawater and freshwater fish pointed out a higher PFCs accumulation in the freshwater species, with perfluorocarboxylic acids being more concentrated than sulfonates.