A review on the environmental radiation levels in different environs of Andhra Pradesh, India

The Andhra Pradesh state, of late, has become major hub for exploration of uranium mineral and it is expected to contribute almost 25% of the nuclear fuel for India's future nuclear energy needs. The extraction of uranium has been initiated in Thummalapally of Kadapa district and the same to be extended in Lambapur, Peddagattu and Chitrial areas of Nalgonda district. The present talk aims to review the available data on radiation levels in these areas along with coal mining areas of Singareni calories, heavy metal mineralization areas of East Coast and different district of the state. The study of radiation levels in these areas and rest of the state at this point of time makes significant for future endeavors. The inhalation of radon and its progeny in dwellings causes much higher dosage compared to other natural sources. Even though thoron and its progeny levels are also important component of the natural radiation environment, relatively less attention was paid to them due to the short half file of thoron. In fact, wherever the thorium content is higher in the soil, the dose due to thoron and its progeny cannot be ignored. In the areas selected for the present review, thorium content is found to be relatively higher and thus the contribution to the dose due to thoron and its progeny is also considered. The reason for elevated radon/thoron concentrations and external background radiation levels in different regions will be discussed. (author)