Radioactivity is a spontaneous disintegration of atomic nuclei by the emission of subatomic particles called alpha particles and beta particles, or of electromagnetic rays called X rays and gamma rays. Radioactivity is dangerous because it can expose people to a harmful dose of radiation even without being aware of the danger. Whenever we go in for X rays for some bone injury often the X ray technologist guides the patient attendants to be behind the cobalt screen to prevent from the unnecessary exposure to the rays and he himself is wearing a protective However some part of the small doses over a long period of time do get into our system and can cause serious diseases like leukemia or cancer in later life.
It is that a very minute but unchanging amount of carbon-14 is present in the atmosphere of the earth and that all living organisms assimilate traces of this isotope during their lifetime. Radiation can lead to the retention of a potentially harmful amount of radium in one’s bones.
Much more dangerous are the nuclear tests conducted by advanced nations. Radioactivity resulting from nuclear bomb tests can cause large quantities of radio strontium and radiocaesuim to get into our food.
