Thallium in food

For humans, food is the most important source of thallium, a heavy metal. T he toxicology of thallium residues is comparable to that of lead and cadmiu m but evaluated differently. According to the analytical data obtained from more than 3000 food items, t he daily intake by humans is assumed to be approximately 2 mu g. In 67% of all samples, thallium concentrations were below the limit of detection (ICP -MS). Measurable thallium concentrations have been found mainly in samples of potatoes, vegetables, mushrooms, spices (containing dried mushrooms) and of tea, coffee and cocoa. In eight samples of kohlrabi and broccoli, conce ntrations exceeded 0.1 mg/kg. The causes of these high concentrations are n ot known; industrial air pollution may be involved. A regular intake of the se food may be detrimental to health. The analytical data presented could b e reason to fix limits of thallium contents in food as the European Commiss ion has been planning for lead and cadmium.