Car-borne survey and dose assessment from external radiation exposure in Bangka Island

With a history of more than 200 years of tin mining, Bangka Island has brought along a byproduct of heavy minerals containing radionuclide elements. There are some concerns about this byproduct material contributing to natural radiation in the environment. In this study, a car-borne survey was conducted to accurately assess natural background radiation in Bangka Island. Indoor and outdoor ambient dose rates in 146 houses were also measured to assess the radiation dose from external exposure received by the public. Soil samples were collected and measured using a gamma spectroscopy system to evaluate the contributions of specific radionuclides to external terrestrial exposure. From 3790 measurement points during the car-borne survey, the highest ambient dose equivalent rate was 596 nSv h(-1) measured in Muntok area, with a mean value of 101 nSv h(-1) and a median value of 95 nSv h(-1). The ambient dose equivalent rate distribution map showed a relatively higher value in the northern coastal area of the island, where the Pemali tin deposit is located. The annual effective dose received from external radiation in the 146 houses in Bangka Island ranged from 0.44 to 1.30 mSv year(-1), with a median value of 0.66 mSv year(-1). The soil contained a relatively high amount of thorium (Th-232), which contributed 69% to external radiation exposure in Bangka Island.

Automated summary

In this study, a car-borne survey was conducted to accurately assess natural background radiation in Bangka Island, which has a history of tin mining for more than 200 years. The study also measured indoor and outdoor ambient dose rates in 146 houses and evaluated the contributions of specific radionuclides in soil samples to external terrestrial exposure. The results showed that the northern coastal area of the island had a relatively higher ambient dose equivalent rate, and thorium (Th-232) in the soil contributed significantly to the external radiation exposure in Bangka Island.