Radon and radon daughters measurement with special reference to uranium mining and its environment

Natural uranium contains mainly uranium-238 (99.28 %). Other constituents are uranium-235 (0.71 %) and uranium-234 (0.0057 %). Radiological hazards due to radionuclides of 238U series are therefore dominant in uranium mining and ore processing. 238U decay ultimately to stable 206Pb by emission of 8 alphas and six beta disintegrations. Uranium is present in the ore from the time of formation of the earth and therefore all daughter products in the series can be considered in equilibrium with 238U. One of the main potential radiological hazards in uranium mining is the exposure to worker to radon daughter concentration prevailing in mine atmosphere. Radon is daughter product of radium-226 the most radiotoxic isotope of uranium-238 decay chain. Radon is an inert gas hence it occurs in atmosphere in mono atomic state. Its short-lived daughter products are always present with radon in atmosphere. The paper describes the monitoring methods for these significant radionuclides