Health Indicator Report of Community Water: Uranium Concentration
Uranium (chemical symbol U) is a weakly radioactive heavy metal that occurs naturally in small amounts in the form of minerals, but it can be processed into a silver-colored metal. It is the heaviest naturally-occurring element that is almost as hard as steel and much denser than lead. Rocks, soil, surface and ground water, air, plants, and animals (including humans) all contain varying amounts of uranium. It can be released into the environment by wind and water erosion and volcanic eruptions. In surface water, uranium can travel long distances. Uranium deposited on land can be re-incorporated into soil, washed into surface water, taken up by plants or adsorbed onto plant roots. Because uranium is found in small amounts everywhere, people can take it into the body from the air, water, food, and soil. However, some geographic regions of the United States, particularly the southwestern states, such as New Mexico have concentrated natural deposits of uranium. For the general public, ingestion of drinking water and food, especially root vegetables, such as potatoes, parsnips, turnips or sweet potatoes grown in uranium-containing soil are the primary sources of uranium exposure. In New Mexico, people may also be exposed through inhalation of radon gas, which is a breakdown product of natural uranium, in their homes, if they live in an area where the amount of uranium (and radium) are high in rocks. In addition, people who own and/or use old uranium-glazed ceramic dishes or collect rock and minerals, may be exposed to uranium. Most of the ingested uranium in drinking water or food leaves the human body in feces and some is absorbed into the bloodstreams and distributed to the various organs. Most of this absorbed uranium is removed from the body by the kidneys and eliminated primarily in urine within a few days. However, some of this absorbed uranium is stored mainly in the liver, kidneys, and bone for many years. Some studies have shown small changes in the way kidneys work when people drink water with large amounts of uranium. These changes, however, seem to go away when people stop drinking this high uranium water. It is unclear what this means medically (see also: https://nmtracking.org/environ_exposure/water-qual_uranium/). Another potential health concern in areas where naturally high levels of uranium occur is the presence of indoor radon. Although not a concern for uranium exposure, bathing and showering with water that contains radon gas dissolved in it may be a health concern; inhalation of radon gas is associated with lung cancer development (More information on indoor radon can be found at https: https://nmtracking.org/environment/Radon.html). Uranium can enter drinking water through the ground or as run-off into surface water sources. Uranium levels in drinking water from most community water systems (CWS) are low, however, there is wide variation in the levels of uranium found in CWS supplies across New Mexico. People who use their private wells water for drinking are solely responsible for testing the water for arsenic (for information about laboratories certified to test drinking water and certified home treatment units visit https://nmtracking.org/environment/water/PrivateWells.html).
NotesData Source: New Mexico Environment Department's Drinking Water Bureau, New Mexico Safe Drinking Water Information System (SDWIS). Measured uranium concentrations in finished drinking water can be used to understand the distribution of potential uranium exposure level for populations served by community water supplies. Due to potential errors in estimating service population, the measures may overestimate or underestimate the number of potentially affected people. These measures allow for comparison of potential uranium exposure between the populations served by different water systems over time.
Data SourceNew Mexico Environment Department, Drinking Water Bureau
Data Interpretation IssuesMeasures alone cannot account for the variability in sampling, number or sampling repeats, etc. Furthermore, concentrations in drinking water cannot be directly converted to exposure because water consumption varies by climate, level of physical activity, and between people. Due to potential errors in estimating service population, the measures may overestimate or underestimate the number of potentially affected people.
DefinitionUranium concentrations (in micrograms of uranium per liter of water or mcg/L) in community drinking water systems (CWS) are combined with information about each CWS (such as service population) to generate the following measures shown in this report: 1) statewide uranium concentration distribution in CWSs by mean and maximum over time, 2) annual distribution of mean and maximum uranium concentration for persons served by CWS and 3) annual distribution of mean and maximum uranium concentration by CWS. EPHT data queries -- https://nmtracking.org/dataportal/query/selection/water/WaterSelection.html -- provide detailed results by year for 1) mean uranium concentration by CWS for a select year, 2) maximum uranium concentration by CWS for a select year, 3) mean uranium concentration and the number of CWS by year, 4) maximum uranium concentration and the number of CWS by year, 5) mean uranium concentration and the number of persons served by year or 6) maximum uranium concentration and the number of persons served by year. Additionally, users may query the number of persons served and the number of CWS in the state for a select year. A CWS is a public water system (PWS) that serves year-round residents of a community, subdivision, or mobile home park that has at least 15 service connections or an average of at least 25 residents. These CWSs are a subset of all New Mexico PWSs. To measure uranium concentration in CWS, drinking water samples are usually taken at entry points to the distribution system or representative sampling points after water treatment has occurred.
NumeratorConcentration of uranium.
What Is Being Done?As of December 8, 2003, the Environmental Protection Agency (EPA) established a drinking water standard or Maximum Contaminant Level (MCL) for uranium of 30 micrograms per liter (30 mcg/L) or 30 parts per billion (30 ppb) to protect public health. This MCL is the highest level of uranium which is allowed in drinking water and it is the enforceable standard. Community systems' drinking water is routinely monitored and tested for uranium by CWS to comply with the 30 mcg/L EPA standard for uranium. In NM, the initial monitoring was required for uranium in 2004. Every year, CWS send to their customers a consumer confidence report (also called a water quality report) that lists any levels of uranium measured. EPA also requires all CWS to give their customers public notice when their water supply violates the uranium standard. This would include information about what is being done to correct the situation. However, people who use their private wells water for drinking are solely responsible for testing the water for uranium (for information about laboratories certified to test drinking water and certified home treatment units visit https://nmtracking.org/environment/Uranium.html).
Page Content Updated On 04/17/2019, Published on 04/18/2019