Uranium poisoning refers to the physiological effects of natural as well as enriched uranium in the human body. Although it is generally poorly absorbed, adverse outcomes may occur due to a combined response to its chemical and radioactive nature, in addition to other closely associated elements.
Uranium poisoning can occur when uranium and its compounds are introduced into the body through various routes like the gastrointestinal tract, skin or lungs, in both soluble and insoluble forms. It is present naturally in the environment, but exposure has been increased in certain communities, due to industrial activities such as working in the uranium mines and mills.
The toxic effects of uranium that have been documented usually reveal because of accidental exposure to extremely high concentrations. These instances have caused fatalities through severe damage to the kidneys and lungs, which are the main target organs. The inhalation of a high quantity of uranium may lead to structural lung damage and chronic airway obstruction. In some cases, this can result in respiratory failure. Most of the uranium that is ingested undergoes rapid ejection, as part of fecal matter and the rest is promptly excreted in urine. Therefore short term subjection to abnormally elevated doses has been known to culminate in acute renal failure and death. The uranium that remains in the body is deposited in bones, where it is absorbed and persists for 1-2 years without causing symptoms [1]. The excess uranium is also deposited in kidneys and liver. Nonetheless, no other organ systems appear to be negatively affected by uranium.
Studies have shown that chronic exposure to low doses of uranium in the environment or workplace does not have a detrimental effect on health [2]. In addition, the consumption of slightly higher quantities, in drinking water, for example, do not lead to renal failure or long-term morbidity [3] [4]. Workers who are exposed to uranium as an occupational hazard do not suffer from poor health and early death because of uranium; illness, on the contrary, is often linked to the simultaneous presence of other harmful substances, such as radon and radium in uranium mines [5] [6]. Those who do sustain renal damage due to long term accumulation recover once the exposure is halted. Despite its theoretical carcinogenic potential due to its emission of alpha radiation, uranium has not practically shown such properties, and neoplastic changes are attributed to co-existing substance toxicity as well.
As the kidneys are the most vulnerable to the effects of uranium poisoning, clinical examination includes urinalysis, assessment of renal function, and the identification of signs of renal disease. Common positive findings in urine include proteinuria, beta-2 microglobulin, and uranium. Conversely, the detection of the latter only indicates uranium contact, however, and helps the clinician to gauge the extent and duration of exposure. It does not necessarily convey concurrent renal damage [7]. Furthermore, it is important to clearly elicit substance exposure history, with particular attention to not only uranium, but also to other closely associated noxious material such as silica dust particles, and even medical history, as they aid and guide in diagnosis [1].