Hazardous profile of uranium and its retention due to prolonged ingestion of groundwater in the geologically heterogeneous Trans-Himalayan region of Ladakh

The young Himalayan mountain range contains a variety of minerals due to the occurrence of diverse geological and geographical conditions, making it conducive to the presence of uranium. Uranium concentrations in drinking water samples of Leh district range from 0.25 µg/L to 95.56 µg/L. Notably, uranium levels exceeding the limits set by international agencies have been detected at some locations, with significant concentrations also found in nearby areas due to the presence of metamorphic, igneous, and sedimentary rocks rich in minerals. Analysis of annual uranium ingestion doses for different age groups highlights that infants aged 0-12 months are particularly vulnerable to uranium exposure. The highest radiation doses are absorbed by bones, followed by kidneys and the lower large intestine, as a result of uranium ingestion. Biokinetic studies suggest that bones serve as the most stable repository for uranium due to the high retention rates compared to other parts of the body. A comparison between the ICRP's biokinetic model for uranium and the Hair Compartment Model (HCM) indicates an increased uranium burden in the human body, as the ICRP model does not account for hair as a pathway for uranium excretion. (author)