Annual Effective Dose from Natural Background Radiation in Pokhara, Nepal

Measurement of outdoor natural background radiation doses at different locations of Pokhara city, Nepal was carried out using GCA-07W, Nuclear Regulatory Commission (NRC) certified Geiger Muller (GM) detector. From the measurements, the least value of background radiation dose rate was found to be 0.26 ± 0.08 μSv/hr for Mahendra Cave area, and the highest value of dose rate was found to be 0.65 ± 0.12 μSv/hr for Prithvi Narayan Campus. The average annual effective dose rate of Pokhara city was found to be 0.56 ± 0.12 mSv/yr ranging from 0.31 ± 0.09 mSv/yr to 0.80 ± 0.14 mSv/yr. The radiation levels in Pokhara, the most populated city of the western development region of Nepal, were found to be within the secure limit for areas of the normal background recommended by the International Commission on Radiological Protection (ICRP) (1 mSv/yr). Further, the current result was compared with the previous study of annual effective dose rate measured in Kathmandu city. Comparable value of the average annual effective dose rate in Pokhara and Kathmandu was obtained.