A Bioassay Analysis of Uranium and Lead in Urine Samples from a High Natural Background Radiation Area in Indonesia

Heavy metal pollution is a major environmental concern due to the high toxicity of heavy metals in humans. High natural background radiation areas (HNBRAs) contain high concentrations of the radioactive element 238U, which decays into 206Pb, in their soil, crops, and water. Concentrations of the heavy metals lead (Pb) and uranium (U) are, thus, correlated with HNBRAs. Mamuju in Indonesia is a recently studied HNBRA where high concentrations of Pb and U in the soil have been reported. The present study analyzes Mamuju residents’ exposure to Pb and U. Two zones in the study area were selected for comprehensive assessment. North Botteng was chosen to represent the HNBRA, and Topoyo was selected as the control zone, with 22 urine samples collected from each zone. The samples were analyzed using a quadrupole inductively coupled plasma mass spectrometer (ICP-MS). The average concentrations of Pb measured in the urine samples were 1.31 mg L−1 and 0.77 mg L−1 in North Botteng and Topoyo, respectively. These values are higher than the urine Pb reference value of 5 µg L−1. The urine Pb concentrations in both studied zones were alarmingly high, which may have serious health effects on the population and should warrant action to reduce Pb exposure in this area. The committed effective dose from the ingestion of 238U in North Botteng was higher than in Topoyo, measuring 36.0 mSv and 8.9 mSv, respectively. The area most affected by the ingestion of 238U was the red bone marrow, followed by the bone surface.