Summary:
Seaweed is becoming a popular food source due to its high nutritional content, but may also contain potentially toxic elements (PTEs). This study investigates trends in PTEs in several species of seaweed collected in Iceland, and variations between thallus section, location, and season. As (3.8-265 mg kg-1), Cd (0.06-18 mg kg-1) and U (0.03-1.9 mg kg-1) were highest in Phaeophyta collected in February, whilst certain Chlorophyta contained the highest levels of Pb ( 0.02-1.8 mg kg-1) and Fe (25-13607 mg kg-1). Samples contained high levels of essential trace elements but elevated levels of Cd – 19 samples exceeded the maximum level (3 mg kg-1) in food supplements. As levels were also high where over half of samples exceeded the 40 mg kg-1 ML for As in seaweed-derived animal feed. Certain species grown in Iceland may be prone to high levels of Cd and not be suitable for consumption in large quantities.