Biokinetic Modelling and Risk Assessment of Uranium in Humans

Abstract

The past few decades have seen substantial experimental and modelling studies addressing the biokinetics of uranium in mammals. Various systemic models have been developed. The degree of absorption of uranium from the gastrointestinal tract is of particular importance and is controlled by the solubility of the uranium compound ingested, previous food consumption and the concomitant administration of oxidizing agents. After entering the plasma, the uranyl ion becomes complexed with bicarbonate, citrate anions and proteins and is dispersed in body tissues. Uranium may then be reabsorbed from various soft tissues, liver, skeleton and kidneys and redeposited or excreted via urine, faeces and hair. The multiple established health effects of uranium ingestion relate to both its chemical and radiological toxicity. Organ-specific and age-adjusted annual effective doses provide insights into possible biomarkers of uranium toxicity in humans. A systematic case study has been carried out in the high-risk-prone area of the Malwa belt of Punjab, India, both estimating the concentrations of uranium in groundwater and evaluating the associated toxicity.