Detecting Low Levels of Radioactivity in Food

Even the food may be a source of weak radioactivity. This is due mainly to the content of potassium, which has the radioactive isotope 40K among its constituents, with a fraction equal to 0.012%. About 30 disintegration per second are expected for each gram of natural potassium. Various foods may have a potassium content of several hundred mg per 100 g of product, so that radioactive decay processes could in principle be detected even by a Geiger counter. Several examples of measurements carried out on different foodstuffs are here investigated.