Identifying sources and environmental risks of emerging mobile organic pollutants in the urban groundwater of Barcelona (Spain)

Groundwater is a vital yet vulnerable resource, subject to contamination from recharge sources and water system leaks by organic pollutants, including personal care products, pharmaceuticals, sweeteners, and industrial chemicals. Despite recent European regulatory progress with the 2022 amendments to Directive 2006/118/EC, many mobile pollutants remain unregulated. This study identified 129 organic compounds, including very mobile pollutants (vM) derived from pharmaceuticals, industrial chemicals, and tyre wear, across 197 urban water samples from Barcelona city. They comprised stormwater, surface water, untreated sewage, nine groundwater samples influenced by river infiltration, rainwater, sustainable urban drainage systems infiltrates, and 32 other groundwater samples. The results showed higher detection frequencies and concentrations of highly polar pollutants (log Dow < 0). Most of the 129 detected compounds were found across all water types, with 41 occurring in stormwater, groundwater, surface water, and sewage, highlighting their widespread presence in urban waters. The study also assessed pollution sources, finding that sewage system leaks and surface water were the main contributors to groundwater contamination, with runoff-associated contaminants such as industrial compounds becoming more prominent as distance from the river increased. The environmental risk assessment highlighted significant risks from pharmaceuticals like atorvastatin, ciprofloxacin, and iopamidol, as well as melamine, showing moderate environmental risk. These findings emphasize the need for continued monitoring to better understand the threats posed by these pollutants to groundwater quality.

This work was supported by the Spanish Ministry of Science and Innovation through the projects WATERPOLLUT (PID2022-138556OB-C21), URBPOL (TED2021-132894B-I00), and UPWATER project (101081807) financed by the EU call Horizon-CL6-2022-ZEROPOLLUTION-01. As well as by the Generalitat de Catalunya-Consolidated Research Groups “2022 2021 SGR 01150- ONHEALTH” and “2021 SGR 00308-MAGH”. Marc Teixidó was also supported by a Ramón y Cajal Contract (funded by the AEI; RYC2022-037083-I). Francesc Labad acknowledges “Agencia Estatal de Investigación” from the Spanish Ministry of Science and Innovation and the IDAEA-CSIC, a Centre of Excellence Severo Ochoa (CEX2018-000794-S) for his predoctoral grant. The authors thank the support from the Barcelona city council through the Award for Scientific Research into Urban Challenges in the City of Barcelona 2020 (reference codes: 21S04651, 21S04652, and 21S04653).

Peer reviewed