| Abstrakt: |
Analysis of activity concentration of natural radioactive elements in volcanic ashes, cold lava and river waters has been carried out due to volcanic eruption of mount Sinabung. It was found the activity concentration of U-238, Ra-226, Th-228, Th-232 and K-40 were 22.62±13.22, 15.10±0.27, 35.45±0.48, 36.55±0.74, 538.78±3.85 respectively for vulcanic ashes and cold lava were 17.46±6.70, 11.72±0.23, 27.01±0.38, 28.76±0.60, 428.56±3.10 for U-238, Ra-226, Th-228, Th-232 and K-40 and for river waters not detected. Risk assessment of the exposure to Gamma radiation from radioactive elements to human and environment in the vicinity of study area were calculated as risk indices. The average radium equivalent (Raeq) for volcanic ashes was of 174.60 Bq/kg, the average absorbed dose rate (D) was of 60.50 nGy/h, gamma index (γi) was of 1.40 and the average of annual effective dose was of 0.084 mSv. Whereas for cold lava was 149.39 Bq/kg, 54.43 nGy/h, 0.471, 0.0476 mSv respectively for Raeq, D, γ and the average of the annual effective dose and for river waters could not detected. The activity concentration and its radiological risk assessment indices were below the limit world. These natural radioactive levels were first study in this area and could be considered a baseline for natural radioactivity levels. [ABSTRACT FROM AUTHOR] |
