Environmental risk classification of emerging contaminants in an alpine stream influenced by seasonal tourism

Over the last few decades, there has been increasing concern about the risks posed by pharmaceuticals and personal care products (PPCPs) in water resources. Despite the awareness of the widespread presence of PPCPs in many aquatic systems, very few studies have investigated the potential risk of these chemicals to wildlife communities of high-altitude freshwaters such as in the Italian Alps. In this context, the two-fold aim of this study was to increase the knowledge about the potential risks of PPCPs to alpine streams subjected to tourism pressure and to investigate the capability of a predictive approach as a useful tool for risk management. The Vermigliana stream (Tonale Pass, Trento Province, Italy) was selected as a case study. Although regional in nature, the selected site is representative of Italian alpine tourism areas. Risk analysis was performed on 54 PPCPs potentially released by the local sewage treatment plant during tourism periods in winter and summer. PPCPs were ranked by risk based on either measured environmental concentrations (MECs) or predicted environmental concentrations (PECs). The results highlighted the potential risks to aquatic organisms, particularly in winter. For instance, the antibiotics amoxicillin and clarithromycin as well as the nonsteroidal anti-inflammatory drugs ibrupofen and diclofenac were above the risk threshold showing MECs or PECs higher than their relative predicted no-effect concentrations. Finally, the risk classifications of PPCPs obtained using PECs and MECs were generally comparable, thereby indicating the potential usefulness of the predictive approach to plan adequate risk management actions. However, over the counter drugs were the only exceptions. The predictive approach misclassified these substances and indicated a lower risk. This highlights the difficulties in identifying the concern posed by these substances in alpine areas characterised by fluctuating population owing to seasonal tourism. Overall, these findings indicate that the proposed risk classification scheme may well be appropriate for prioritization of PPCPs in the alpine environments characterized by high tourism pressure, when robust and local data are available and reflective of most source inputs.