Low-level radioactivity measurements on aluminum, steel and copper☆

Abstract The radioactive contamination levels in samples of aluminum, steel and copper, supplied by a number of producers of these materials have been measured and activities have been assigned to possible natural radioelements. These activities were found to lie in the range of 0·02–0·6 pCi/g of parent radionuclide. The decay with time of some contaminants has been observed. A few measurements were also made on a number of other materials.