Bioaccumulation of environmental pollutants and marine toxins in bivalve molluscs: a review

Seafood is both nutritionally and economically significant, with bivalve molluscs being particularly valuable for monitoring environmental pollutants due to their filter-feeding nature and ability to bioaccumulate pollutants. While not often linked to food poisoning, these molluscs can occasionally introduce health risks, highlighting the need for vigilant monitoring. This review provides a thorough analysis of pollutants—including persistent and emerging pollutants, as well as marine toxins—found in bivalve molluscs between 2019 and 2024. Among the studied pollutants, plasticizers and alkaloids are the most frequently analyzed, with liquid and gas chromatography (GC) tandem mass spectrometry (MS) the predominant methods, although novel approaches to determine these compounds, such as sensors, have also emerged in recent years. However, many studies are focused on establishing pollutant content without addressing bioaccumulation (BA) factors, and a lack of standardization in species and sampling locations complicates comparisons between the different published works. Despite some studies linking human activity and algal blooms to BA dynamics, more comprehensive research is needed. Additionally, limited data on the depuration capacity of molluscs underscores the need for further investigation. Although pollutant levels generally remain within legal limits, many substances remain unregulated. Environmental factors also play a critical role in influencing BA, emphasizing the need for future studies to focus on BA factors to better understand these complex dynamics.