Soil-to-banana transfer factor of radionuclides in Lampung, Indonesia

This study estimates the soil-to-banana transfer factor of radionuclides in southern of Lampung, Indonesia, a region influenced by a large coal-fired power plant (CFPP) and other heavy industrial activities. This region is renowned for its banana productions, exceeding 11,000 tons annually for both local consumption (notably greater Jakarta) and export. Coal combustion in CFPP concentrates natural radionuclides from a series of uranium and thorium within the resulting ash. Soil and banana samples from Srengsem, Mataram, and Rangai Tri Tunggal villages were analyzed for ²²⁶Ra, ²³²Th, and ⁴⁰K using a calibrated P-type High-Purity Germanium (HPGe) detector. The study found average activity concentrations in soil were 26 ± 1 Bq kg^-1 for ²²⁶Ra, 28 ± 1 Bq kg^-1 for ²³²Th, and 368 ± 12 Bq kg^-1 for ⁴⁰K. In banana, ²²⁶Ra at 6 ± 1 Bq kg^-1 and ⁴⁰K at 288 ± 10 Bq kg^-1 (⁴⁰K) were detected, while ²³²Th below of limit detection. The transfer factors for ²²⁶Ra and ⁴⁰K were counted at 0.3 ± 0.2 and 1.6 ± 1.3, respectively, showing medium to high uptake. The estimated effective dose was significantly below the BAPETEN limit of 1 mSv year^-1, confirming that bananas cultivated in southern of Lampung area are safe for human consumption with minimal radiological impact. The findings underscore the critical insights into the safety of agricultural products produced in regions impacted by industrial activities and provides data for support the development of robust national food security management strategies.