Monitoring of Contaminants of Environmental Concerns along the coastlines of the Mediterranean Sea: the ONE-BLUE project

The Mediterranean Sea is a semi-enclosed basin that is exposed to intense anthropogenic pressure. The presence of emerging contaminants in this area is a growing concern for the integrity of the ecosystem and human wellbeing. The continuous input of pollutants from coastal urbanisation, industrial activities, agriculture, maritime transport and tourism creates a dynamic and complex contamination scenario, in which many of these pollutants are not well characterised. In this context, the ONE-BLUE project aims to strengthen transnational knowledge and monitoring capacity by evaluating the occurrence and distribution of emerging contaminants across key sub-regions of the Mediterranean. The study addresses the challenges of identifying priority contaminants, understanding their spatial patterns and supporting the development of harmonised monitoring strategies. To this end, surface and column water and sediment samples were collected in six representative Mediterranean areas: the Spanish coast, the Tyrrhenian Sea, the Ionian Sea, the Adriatic Sea and the Aegean Sea. Samples were extracted on board or in temporary laboratories near the sampling areas within 24 hours of collection to minimise degradation and ensure analytical reliability. The extracts were analysed using liquid chromatography coupled with mass spectrometry (LC-MS) to quantify a wide range of emerging pollutants, including pharmaceuticals, residues of personal care products, industrial chemicals, and other markers of human activity. Overall, the ONE-BLUE investigation will provide a valuable evidence base for assessing environmental risk, guiding mitigation efforts, and informing policymakers on priority substances requiring targeted management.