The south west coastal region of Kanyakumari district is witnessed as a Naturally High Background Radiation Area. The outdoor Gamma radiation level and concentration of radon, thoron and their progeny level were measured using Environmental Radiation Dosimeter and Solid State Nuclear Track Detector(SSNTD) method. For assessing the environmental radiological impact to public it is essential to evaluate the activity levels of these daughter products of Uranium.. The gross alpha and gross beta activities of drinking water collected from bore wells were estimated for radiological assessment. Results of the Gamma ray spectrometric measurements carried out for natural radioactivity levels due to 226Ra, 232Th and 40K in the beach sand samples. The total dose rate was also calculated and the results are reported in this paper. This study provides a baseline data of radioactivity background levels in the coastal regions of Kanyakumari district from Colachel to Midalam and will be useful to assess any changes in the radioactive background levels.

Keywords : Radon, Thoron , Radiation level, dose