An overview of the contaminant mixtures present in key consumed fish and seafood species along the Portuguese territory.

Abstract

This study evaluates the concentrations of potentially toxic elements - mercury, arsenic, cadmium, lead and selenium - in seven marine species (Xiphias gladius, Aphanopus carbo, Merluccius merluccius, Helicolenus dactylopterus, Loligo vulgaris, Cancer pagurus and Ruditapes decussatus) across different locations in mainland Portugal and the Azores. The results showed a significant interaction between species and site, indicating that elemental concentrations varied by species and sampling site. This highlights the complex interplay of biological and environmental factors, such as habitat, feeding habits and local sources of contamination. Mercury and arsenic were the elements of most concern. Mean mercury concentrations ranged from 0.84 mg kg-1 wet weight in A. carbo to 0.073 mg kg-1 wet weight in R. decussatus, while arsenic levels varied from 6.65 mg kg-1 in C. pagurus to 0.09 mg kg-1 in X. gladius. Risk assessment calculations often exceeded safety limits. The hazard index for C. pagurus reflected a worrying combination of several contaminants at high levels, with M. merluccius presenting the lowest consumption risk, with lower contaminant concentrations and associated health risks. The data highlight the different risks posed by different species: X. gladius and A. carbo had the highest mercury contamination, while C. pagurus and R. decussatus exceeded arsenic limits for all risk assessment calculations. These results highlight the need for continuous monitoring and risk management to ensure the safety of seafood in the region.