Mercury exposure during pregnancy and the effect of harmonised fish-consumption advice: results from the multi-country randomised HBM4EU-MOM study
Year: 2026
Type: article
Study design: Clinical Trial
Abstract: Mercury exposure during pregnancy remains a public health concern due to its potential impact on foetal neurodevelopment. The randomised HBM4EU-MOM study (2020-2022) evaluated the effect of harmonised dietary advice on mercury exposure among 654 pregnant women from five European coastal countries. Total mercury concentrations in hair were measured at Phase 1 (baseline) and Phase 2 (follow-up). At baseline, mercury exposure varied substantially across countries, with the highest geometric mean (GM) concentrations in Portugal (1.56 μg/g) and Spain (0.90 μg/g), and lower levels in Greece, Iceland, and Cyprus (0.44 μg/g, 0.36 μg/g, and 0.31 μg/g, respectively). The primary adjusted analysis (n = 600) showed no evidence that the dietary intervention reduced follow-up hair mercury concentrations compared with the control group (adjusted geometric mean ratio [GMR] = 1.028, 95% CI 0.955-1.107; p = 0.455). Between baseline and follow-up, the GM mercury concentration across pooled participants with paired measurements decreased from 0.59 μg/g to 0.55 μg/g (-6.79%, p = 0.002), with statistically significant temporal reductions observed in Spain and Portugal, while no statistically significant temporal changes were observed in Greece, Iceland, or Cyprus. The proportion of women exceeding the EFSA exposure benchmark (1.8 μg/g) decreased from 12.5% at baseline to 7.5% at follow-up. Country-specific temporal reductions in Spain and Portugal were observed in both intervention and control groups with similar magnitudes. These findings indicate that the observed temporal decline in mercury exposure during pregnancy cannot be attributed specifically to the harmonised dietary intervention and is likely to reflect factors operating beyond the intervention itself. Although the intervention did not produce a measurable reduction in mercury exposure compared with standard care, the country-specific temporal patterns and reductions in the proportion of women exceeding health-based exposure benchmark highlight the importance of understanding the behavioural, dietary, and contextual factors influencing mercury exposure during pregnancy.
Source: Environment International
Authors: Catherine Gabriel, Marta Esteban-López, Sónia Namorado, Thorhallur I. Halldorsson, Janja Snoj Tratnik, Achilleas Karakoltzidis, Dayna R. Schultz, Elena Anastasi, Ricardo Assunção, Susana Pedraza-Diaz, Argelia Castaño, Anthoula Chatzimpaloglou, Noelia Domínguez-Morueco, Despina Giannadaki, Sara González, Milena Horvat, Eva Jacobsen, Spyros Karakitsios, Marike Kolossa-Gehring, Miguel Ángel Lucena, Carla Nunes, Kristin Olafsdottir, Nafsika Papaioannou, Maria Peres, Ana I. Cañas-Portilla, Laura Rodriguez Martin, Maria Rodríguez, Ana Rodríguez, Susana Santiago, Anthi Thoma, Dimosthenis Sarigiannis, Andromachi Katsonouri
Institutions: Aristotle University of Thessaloniki, Instituto de Salud Carlos III, Centro Nacional de Sanidad Ambiental, National Institute of Health Dr. Ricardo Jorge, Comprehensive Health Research Centre, Universidade Nova de Lisboa, University of Iceland, Jožef Stefan Institute, Jožef Stefan International Postgraduate School, Ministry of Health, Escola Superior de Saúde Egas Moniz, Institute for Prevention and Occupational Medicine, Ruhr University Bochum, Flemish Institute for Technological Research, Istituto Universitario di Studi Superiori di Pavia, National Hellenic Research Foundation
Language: English
Subfield: Health, Toxicology and Mutagenesis
Field: Environmental Science
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $4,750
OpenAlex ID: W7223059332