Radiation hazards from natural radionuclides contained in rice from former tin mining land

Abstract

BACKGROUND AND OBJECTIVES: Rice (Oryza sativa L) cultivated at former tin mining land has the potential to absorb natural radionuclides from the soil where it grows. Radionuclides found in rice can potentially lead to exposure to ionizing radiation, thereby influencing the likelihood of developing. The aim of study is to assess the levels of natural radionuclides in rice, calculate the annual effective dose, and evaluate the additional lifetime cancer risk resulting from radiation exposure via the consumption of rice.METHODS: Rice sampling was carried out, then 1 kilogram was weighed and sealed in a standard Marinelli container. Placed for approximately 30 days before gamma spectrometer measurements to allow the decay products to reach secular equilibrium. Utilizing a high purity germanium detector, the radioactivity of the samples was quantified through a gamma spectrometer. Data obtained to calculate daily intake of radionuclides, annual effective dose, and Lifetime Cancer Risk probability.FINDINGS: Rice sourced from previous tin mining areas in Indonesia has been considered safe for consumption. While radium and uranium were not detected in the rice, elevated levels of Thorium and Potassium were observed, exceeds the reference value. The estimated annual effective dose that people receive by consuming rice is still lower than the annual limit for the general public recommendation and the world average. The estimated risk of Indonesian people getting cancer due to rice consumption is 1.23 people per 10,000 population, lower than reference value (2.9 people per 10,000 population). The absence of cancer risk associated with this method indicates that the agricultural land in Bangka Belitung Province remains suitable for rice cultivation. This finding has holds significance within the realm of environmental risk assessment.CONCLUSION: Rice samples obtained from former tin mining land actually did not contain the natural radionuclides radium and uranium, but radionuclides thorium and potassium were found. The concentrations of radionuclides thorium and potassium exhibited variations in activity levels, surpassing the reference value but remaining below the global average threshold. The annual effective dose is still lower than the average annual intake dose in the world. The estimated risk of cancer from consuming rice was found to be 1.23 people per 10,000 population or a range of 0.55 to 2.67 people per 10,000 population who are potentially at risk of developing cancerThe lifetime risk of cancer-related death is reported to be lower than the public recommendation, with 2.9 individuals per 10,000 population being affected. Rice consumers from former tin mining areas in Indonesia (Bangka) continue to be classified as safe.

Keywords

• natural radionuclides
• radiation hazards
• rice
• tin mining