Environmental contamination by the NORM industry: challenges for radioecology

Apart from the obvious presence of naturally occurring radionuclides (NORs) in uranium deposits, a wide range of uranium- and thorium-bearing minerals (and daughters) are being mined and processed commercially. In most minerals, natural levels of radionuclides are very low. In others, e.g. zircon and rare earths the concentration of 238U and 232Th may be considerably elevated. Enhanced levels of NORs may be associated with abandoned waste dumps, installations and surroundings from certain industries, involved in the extraction or processing of raw materials containing NORs. This can result in considerable exposure to the public and affect the environment. The most prominent examples in Europe are, apart from the residues of uranium mining and milling, the waste generated by the phosphate processing industry, the scales from the oil and gas extraction industry, the ashes from the power production from coal and the slag produced by the metal mining and smelting industry.