Toxic heavy metals in drinking water seriously affect human health and this raises more and more concerns. When one speaks of heavy metals, one speaks of “radioactivity”. Among those materials is uranium. The dangers of uranium contamination of water are primarily related to the toxic chemical effects of heavy metal accumulation. Uranium is a naturally occurring metal that is the heaviest component of the natural environment and is found in rocks, soil, water, air, plants, and animals. Because uranium is almost ubiquitous in the environment – although at varying levels – exposure to heavy metal is unavoidable.
In addition to the presence of natural uranium in the environment, current sources of uranium contamination include abandoned uranium mines, the dissolution of uranium-containing minerals in groundwater, mill residues, emissions from the nuclear industry, and the combustion of coal or other fuels. Exposure to uranium may result in radiological and chemical toxicity, but when it comes to tapping water, the toxicity of uranium to heavy metals is of greater concern.
Although most ingested uranium is excreted by the body (through urine and feces), small quantities can be absorbed and transported through the bloodstream to the internal organs. Scientifically, the process is referred to as bioaccumulation. The toxicity of uranium can affect different organs and bones, but the kidneys are the most susceptible organ to uranium than other organs. When uranium is filtered into the bloodstream by the kidneys, the compounds may cause serious damage to kidney cells. The kidneys can be repaired within a few weeks at low levels (less than 25 mcg). When ingested in sufficient quantities (50 to 150 mcg, depending on the individual), uranium toxicity may lead to acute kidney failure and therefore death.
Unlike many chemicals of concern, uranium contains maximum concentrations of contaminants identified by the U.S. Environmental Protection Agency under the Safe Drinking Water Act. Maximum Levels of Contamination (MCL) determine the maximum contaminant based on the economic feasibility of the treatment and health effects, assuming a person drinks two liters of water daily for 70 years. The MCL of uranium in tap water is 30 µg/L. Uranium levels above the minimum MCL are toxic and can damage the kidneys over time and increase the risk of cancer over time.
First, it is important to note that these main health effects are due solely to high concentrations of uranium, which means higher levels than what we see in well water. However, we recommend that well owners carry out tests to detect the presence of uranium and even other possible contaminants. If you find that your well water contains more than 20 mcg/L, you can use bottled water until the problem is solved. Process your water (reverse osmosis or anion exchange), move to a surface water supply. If you use a public water supply, you can view consumer trust reports for water network testing. Of course, you can also obtain a water quality report specific to well water or town water that tests uranium among 30 other heavy metals and other significant contaminants.