All life is being constantly exposed to various forms of radiation - visible light, infrared, ultraviolet, radio waves, X-rays (from cosmic and terrestrial sources) and particulate cosmic rays - all of which constitute the biological effects of radiation, which can be both normal and abnormal or injurious. This book, aimed primarily at discussing the deleterious effects of radiation, presents a study of natural and man-made radiations, dramatic discoveries in radiation and major accidents in industries, problems and risks of nuclear energy including the disposal of radioactive wastes as against the benefits when compared to other sources of energy.