Uranium

A radioactive metallic element with the chemical symbol U. Uranium occurs naturally in soils and rocks, and trace amounts reach foods and drinking water through geology and — historically — phosphate fertilizers and mining contamination. Both its chemical toxicity (kidney damage) and radiological hazard are assessed in food-safety evaluations, and international health agencies have issued guidance values for uranium in drinking water. Typical dietary intakes from uncontaminated areas are very low. Monitoring programmes test water supplies in high-background regions, and remediation focuses on water treatment rather than food-chain intervention, since plant uptake is limited.