Arsenic in edible macroalgae: an integrated approach

Arsenic is a metalloid naturally present in marine environments. Various toxic elements including arsenic (As) are bioaccumulated by macroalgae. This metalloid is subsequently incorporated as arsenate into the organism due to similarity to phosphate. In recent decades, the use of macroalgae in food has increased as a result of their numerous benefits; however, As consumption may exert potential consequences for human health. The objective of this review was to discuss the articles published up to 2019 on As in seaweed, including key topics such as speciation, toxicity of the most common species in marine macroalgae, and their effects on human health. Further, this review will emphasize the extraction methods and analysis techniques most frequently used in seaweed and the need to develop certified reference materials (CRMs) in order to support the validation of analytical methodologies for As speciation in macroalgae. Finally, this review will discuss current legislation in relation to the risk associated with consumption. The number of articles found and the different approaches, biological, analytical and toxicological, show the growing interest there has been in this field in the last few years. In addition, this review reveals aspects of As chemistry that need further study, such as transformation of organic metalloid species during digestion and cooking, which necessitates analytical improvement and toxicological experiments. Taken together our findings may contribute to revision of current legislation on As content in edible seaweed relating to human health in a growing market.