Explanation:

Naturally Occurring Radioactive Materials and Technologically Enhanced Naturally Occurring Radioactive Materials consist of materials, usually industrial wastes or by-products enriched with radioactive. Natural radioactivity was discovered by Henri Becquerel in 1896 by using naturally fluorescent minerals to study properties of X-rays. Radiation sources can be natural or artificial (man-made). ... Cosmic radiation is caused by radionuclides, which are formed by the interaction of cosmic rays arriving from stars, and especially the Sun, with the nuclei of elements present in the atmosphere (oxygen and nitrogen).