Food safety hazards in the European seaweed chain

Seaweed is a source of protein that can help overcome the anticipated challenges of a growing world population and the current challenges for finding alternatives for animal proteins in the Western diet. Thus far, data on the safety of seaweed for feed and food purposes in the Western world are scattered. This study aimed to review the available knowledge on the presence of food safety hazards in seaweed, including factors influencing their presence, and to prioritize the hazards that may pose a risk to human health. Given current knowledge from the literature, data from the Rapid Alert System for Food and Feed, and results from a stakeholder survey, 22 food safety hazards were ranked into major (4), moderate (5), and minor (13) hazards. Arsenic, cadmium, iodine, and Salmonella were identified as major hazards. Hazards, where data gaps exist, should be carefully assessed. These include pesticide residues, dioxins and polychlorinated biphenyls, brominated flame retardants, polycyclic aromatic hydrocarbons, pharmaceuticals, marine biotoxins, allergens, micro- and nanoplastics, other pathogenic bacteria, norovirus, and hepatitis E virus. It is recommended to collect more data on these hazards in future studies. Many factors can affect the presence of hazards including seaweed type, physiology, season, harvest and cultivation environment, geography including the location of cultivation, alongside further processing. Moreover, when seaweed is cultivated near industrialized or anthropogenic activities, these activities may negatively influence water quality, which can increase the likelihood of hazards in seaweed. Results of the ranking prioritized hazards can be used to prioritize monitoring programs and adjusted given future additional knowledge covering the data gaps.