Radium in Drinking Water

What Is Radium? Radium (Ra) is a naturally occurring radioactive element that is present in varying amounts in rocks and soil within the earth’s crust. Small amounts of radium also can be found in groundwater supplies. Radium can be present in several forms, called isotopes. The most common isotopes in Illinois groundwater are Ra-226 and Ra-228. The main type of radiation emitted by radium is the alpha particle. What is radioactivity and how is it measured? Radioactive substances are unstable in nature and release energy in a process called radioactive decay. The energy can be in the form of a wave (for example, gamma rays) or a particle (for example, alpha and beta particles) or both. Scientist can identify the different types of radioactive elements by measuring the characteristics of this energy. In the U.S., radioactivity is usually measured in units called "curies". The level of radioactivity in water is very low and is measured in picocuries (one picocurie equals one-trillionth of a curie) per liter, written pCi/l. The first step in determining the level of radium in drinking water is the "short-term gross alpha test". The term "gross" means "total". Most naturally occurring radioactive elements emit alpha particles as they decay. Detection of alpha particles in the water signals the presence of specific radioactive substances, possibly radium 224 and radium 226. Radium 224 decays quickly, and, therefore, only those analyses which are conducted soon after collection will include the contribution from radium 224. There are other radioactive substances, besides radium, that may contribute to the gross alpha radiation in water. Analyses for these substances is usually not necessary. Is Radium In My Water? Surface water is usually low in radium but groundwater can contain high levels of radium depending on local geology. Deep bedrock aquifers used for drinking water sometimes contain levels of Ra-226 and Ra-228 that exceed health-based regulatory standards. In Illinois, high radium levels occur primarily in the northern third of the state due to the presence of radium in the granite bedrock that surrounds aquifers from which water supplies are drawn. Most of the private wells in Illinois draw their well water from aquifers that are much shallower than those used by public water supplies. Most shallow aquifers do not contain higher levels of radium. However, radium has been found in some private and public wells. Radium cannot be seen, tasted, or smelled in your drinking water. Unless your private water supply has been tested for radium, you should not assume your water is radium-free. All public water supplies are tested regularly for radium. Is Radium In Water Harmful To My Health? Radium in water may pose a hazard to human health when the water is used for drinking or cooking. Only a small portion of ingested radium is absorbed from the digestive tract and distributed throughout the body. The rest is passed unchanged from the body. Some absorbed radium is excreted in urine. Absorbed radium behaves similarly to calcium and is deposited in the tissues of the body, especially bone. Any radiation received externally through showering, washing, or other uses is not a hazard since alpha particles do not travel through your skin. Internally deposited radium emits alpha particles that may then damage surrounding tissue. Studies of workers exposed to high levels of radium and other sources of alpha radiation for extended periods show that high levels of radium may cause depression of the immune system, anemia, cataracts, and fractured teeth. Exposure to high levels of radium also has shown an increased incidence of bone, liver and breast cancer.  Limits and Health Effects The EPA has set a limit for combined radium in drinking water at 5 pCi/L (picocuries per liter) as being protective of human health. Long-term exposure to radium increases the risk of developing certain cancers. These effects usually take years to develop. Map This map shows the areas of South Carolina where unsafe levels of radium have been found. The upper coastal plain is the region of greatest risk, however radium at unsafe levels can be found elsewhere, especially in the Piedmont and the York County area.  Is There A Test To Determine If I Have Been Exposed To Radium? If you think that you have been exposed to radium in your drinking water, you should consult your doctor. Urine tests can determine if you have been exposed to radium. Another test measures the amount of radon (a breakdown product of radium) in exhaled air. However, these tests cannot tell how much radium you have been exposed to or if adverse health effects will occur. What are the health concerns relating to radium in drinking water? There are no immediate health risks or symptoms from drinking water that contains radium. However, it may cause health problems over time. Radium is radioactive and decays very slowly. During this process, radiation is released. The health effects of exposure to radiation vary according to how long a person is exposed and how much radium or radiation a person is exposed to. Over decades, exposure to radium can increase the risk of bone cancer. Return to Top Can radium be removed from drinking water? Yes. A water softener (also called a cation exchange unit) is able to remove nearly all radium found in drinking water. In the softener, radium is exchanged for sodium or potassium. When the softener is cleaned, the radium is flushed away with the wastewater. With this type of treatment, the sodium or potassium remains in the drinking water. Another type of treatment called reverse osmosis has also been shown to remove most radium from drinking water. In this process, water is forced under pressure through a membrane leaving the radium behind. The radium is then flushed away. This process is slow and more suitable for a household well than for a public water system. With either type of treatment, proper operation and maintenance are essential. If radium contamination is discovered, some public water systems choose to abandon the well and connect to a neighboring supply rather than treat the drinking water. Another option for the water system is to blend their well water with another water supply that meets the standards to produce reduced-radium water.