These are the radiations produced by man through various activities and the greatest exposure to human beings comes from the diagnostic use of X-rays, radioactive isotopes used as tracers, radium-dial wrist watches etc.

Also during the treatment for cancer and other ailments some people receive heavy radiation doses. Radioactive wastes given off by nuclear generator also constitute a potential radiation hazard.

The increasing demand for energy in the world and developing countries has necessitated the establishment of numerous atomic power plants. These activities have becomes perilous source of radiations. Wastes coming from the production of nuclear weapons e.g. Plutonium, Strontium, and Celium etc. are also carcinogenic. The nuclear wastes such as contaminated dust, debris, gloves, shoes etc when dumped into the disposal sites can delite the atmosphere and even seep into the soil and pollute the drinking water.