We live in radioactive world. The exposure of living beings to the natural and manmade ionizing radiation have adversely affected the health of mankind causing short and long term biological consequences and hence is the major cause of concern for the past about hundred years . Various international agencies like UNSCEAR, ICRP, WHO, IAEA, ICAR, OECD, NEA, US EPA, etc. are regularly monitoring the radiation levels, exposure of the public, its health effects and thereby are giving recommendation for the control and protection from radiations. For the detailed investigations for natural...