Environmental risk assessment for contaminants of emerging concern in the Belgian part of the North Sea

• Published in: Integrated environmental assessment and management
• Main Authors: Zhang, Qiyun, Hansul, Simon, Samuel, Moeris, Vanhaecke, Lynn, Demeestere, Kristof, De Schamphelaere, Karel
• Format: Journal Article
• Language: English
• Published: England 22.07.2025
• Subjects: passive sampling; North Sea; contaminant of emerging concern; Marine Strategy Framework Directive; ecotoxicity
• ISSN: 1551-3777; 1551-3793; 1551-3793
• DOI: 10.1093/inteam/vjaf092

Belgian coastal waters are influenced by densely populated cities, industrial activities, and marine shipping, and they are therefore subject to chemical contamination. In the NewSTHEPS (New Strategies for Monitoring and Risk Assessment of Hazardous Chemicals in the Marine Environment With Passive Samplers) project (2012–2019), more than 150 contaminants of emerging concern (CECs) were detected in the Belgian part of the North Sea, including hormones, personal care products (PCPs), pesticides, nonhormone pharmaceuticals, phenols, and phthalates. In this study, we developed and used an automated algorithm to calculate the marine screening level predicted no-effect concentration (PNECscreen) of substances and identify the organisms and organism groups most sensitive to these chemicals based on ecotoxicological data from the ECOTOX Knowledgebase. By combining these PNECscreen values, existing environmental quality standards (EQSs) from the EU Water Framework Directive (WFD), and PNECs from other sources with environmental concentrations of substances measured in the NewSTHEPS project, we assessed the risk of different classes of CECs at four sampling stations. The distribution of risk was comparable between open sea and harbor sampling locations, and also between samples collected with grab sampling and passive sampling. In total, 33 substances, including 11 hormones (natural and synthetic ones), two PCPs, four pesticides, eight nonhormone pharmaceuticals, two phenols, and six phthalates, were found to be associated with potential environmental risk (median risk quotient > 1), with fish most frequently being the most sensitive organisms. The majority (23/33, i.e., > 80%) of these substances, particularly hormones and phthalates, have not been included in the EU WFD EQS directive’s Priority List or associated Watch Lists. Although the risks associated with pharmaceuticals were primarily driven by individual substances, hormones, phthalates, and pesticides with endocrine disrupting and/or neurotoxic potentials were estimated to contribute to a “something from nothing” effect, where mixture risk arises even when all individual components are present at concentrations below their effect thresholds.