Uranium (U) is a silver-white metal that is highly dense and weakly radioactive. It usually occurs as an oxide extracted from ores containing less than 1% natural uranium. Natural uranium is a mixture of three isotopes: 238U (greater than 99%), 235U (about 0.72%), and 234U. 238U has a half-life of 4.5 X 109 years. It decays by alpha emission to produce 234Th, the initial step in a decay chain that eventually leads to lead. Alpha, beta, and gamma emissions occur during this decay process. This test's measured result (238U) does not reflect or imply exposure to enriched 235U. Uranium has many commercial uses, including nuclear weapons and nuclear fuel, in some ceramics, and as an aid in electron microscopy and photography.
The chemical effects of uranium 238U may be more severe than the radiochemical effects. Uranium can combine with phosphate, citrate, pyruvate, malate, lactate, etc., in body tissues and usually is transported in the blood as a carbonate complex. Uranium that is not excreted in urine can accumulate in bone and kidney tissues as well as in the spleen and liver. In excessive amounts, it can be nephrotoxic. Inhaled uranium accumulates in lung tissue. Fatigue is the most common symptom associated with chronic, low-level uranium exposure.
Uranium is more common than mercury, silver, or cadmium in the earth's rock strata and may be present, at low levels, in drinking water.
How can Uranium affect health?
Uranium can significantly affect human health, mainly if exposure occurs at high levels or over extended periods.
- Radiation Exposure: Uranium is radioactive, and its decay products emit alpha, beta, and gamma radiation. Chronic exposure to these radiation types can damage tissues and DNA, potentially leading to cancer, particularly in the lungs, bones, and kidneys.
- Chemical Toxicity: Uranium is a heavy metal with radioactive properties, and its chemical toxicity can affect various organs. Chronic exposure to high levels of uranium can lead to kidney damage, as the kidneys are responsible for filtering and excreting uranium from the body.
- Inhalation: Inhalation of uranium dust or aerosols is a significant route of exposure, particularly in occupational settings such as uranium mining or processing facilities. Inhalation can lead to lung cancer and other respiratory issues.
- Ingestion: Ingestion of uranium-contaminated food or water can also lead to health problems, particularly affecting the kidneys and bones. Chronic ingestion of uranium can result in kidney damage and increase the risk of developing kidney disease.
- Environmental Exposure: Individuals living near uranium mining or processing sites may be exposed to elevated levels of uranium through air, water, or soil contamination. This environmental exposure can increase the risk of various health problems, including cancer and kidney disease.
- Pregnancy and Children: Pregnant women and children are particularly vulnerable to the effects of uranium exposure. Uranium exposure during pregnancy can impact fetal development and increase the risk of birth defects and developmental disorders.
Minimizing exposure in occupational and environmental settings is crucial for mitigating the health risks associated with uranium exposure. Regularly monitoring uranium levels in biological samples, such as urine and blood, can help assess and manage exposure risks.
How can one determine if one has been exposed to Uranium?
There are two types of tests. One checks for exposure to large doses of radiation, and the other checks whether and in what quantity Uranium is present in the body. The first type of test looks for changes in blood cells or chromosomes, but it is impossible to determine whether the radiation originates from Uranium. The second type of test includes blood, stool, urine, and saliva.
We can measure Uranium levels in the blood and most biological materials.
Determination of metals is done by ICP-MS (Inductively Coupled Plasma Mass Spectrometry), a method that enables the simultaneous detection of many metals. Its sensitivity and accuracy are significantly better than conventional atomic absorption, with the ability to measure metals at concentrations up to 1 in 1015 (1 in 1 quadrillion, ppq)!
