MEASUREMENT RADON EMANATION FROM SOIL IN BENGKULU CITY

Abstract

Since radon emanation from soil is one of the most important factors for the evaluation of environmental radon levels, it is essential to develop an effective, economical and practical method for the classification and mapping, then it would be useful for identifying areas with a risk of high radon exposure. In field measurements, we measured radon gas concentration from 28 points from different area in Bengkulu in order to make a rough estimation of the radon emanation from soil in Bengkulu. Considering the applicability to the large area in Bengkulu, a simple model was established by eliminate some physics parameters. In the laboratory we calculated number atom of gas radon by using detector Geiger Muller (GM) tube. In order to counter only radon gas in the canister, we use filter GF/A, then only particle alpha from radon, which were measured. Average radon concentration in Bengkulu city is 427 Bq/m³, which is implying still under threshold value that is allowed in environment. We found radon emanation in range 0.3 up to 0.6 Bq/m/s. In spite of the large uncertainties in the model which is influenced by so many factors, the considerable validation of the model can be shown, but for accurate measurement, important mechanisms, such as advection, adsorption, porosity and density of the soil should be considered in the future work.

Key words : radon gas, emanation, concentration, Bengkulu