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Radiation Protection

Technologically Enhanced Naturally Occurring Radioactive Materials (TENORM)

Technologically Enhanced Naturally Occurring Radioactive Material (TENORM) is defined as, "Naturally occurring radioactive materials that have been concentrated or exposed to the accessible environment as a result of human activities such as manufacturing, mineral extraction, or water processing.” 1

"Technologically enhanced" means that the radiological, physical, and chemical properties of the radioactive material have been concentrated or further altered by having been processed, or beneficiated, or disturbed in a way that increases the potential for human and/or environmental exposures.

Naturally Occurring Radioactive Material (NORM) is defined as, “Materials which may contain any of the primordialHelpprimordialExisting from the beginning of time, naturally occurring. radionuclides or radioactive elements as they occur in nature, such as radiumuranium, thorium, potassium, and their radioactive decay productsHelpdecay productsThe atoms formed and the energy and particles emitted as radioactive material decays to reach a stable form., such as radium and radon, that are undisturbed as a result of human activities." 1

Background radiation, which is present in terrestrial, cosmic, and cosmogenic sources, is always around us. Some man-made radioactivity is considered part of background for regulatory purposes (e.g., fallout from weapons testing).

Learn about radon, a naturally occurring radioactive gas found in soils, rock, and water throughout the U.S.

TENORM Industries and Sources

Radioactive elements are present in many soils and rock formations, and consequently in the water that comes into contact with them. Extraction and processing of these resources may expose or concentrate NORM, causing them to be classified as TENORM.

This list of TENORM sources is not comprehensive, as TENORM is known to occur in other processes, but provides a general sense of the hazards posed by this class of radioactive substances. The major industrial sectors that generate TENORM are:

EPA's Role

EPA is working to understand the problems associated with TENORM and to develop effective ways to protect people and the environment from unnecessary exposure to the radiation from these materials. Because TENORM is generated by many industries in varying amounts and occurs in a wide variety of products, the management of TENORM is a complex issue. Although EPA and others working on the problem have already learned a great deal about TENORM, we still do not completely understand all the potential radiation exposure risks it presents to humans and the environment.

EPA is investigating TENORM challenges in three ways:

  • Studying the TENORM-producing industries to characterize their residuals and wastes, and evaluate potential exposures.
  • Identifying and studying TENORM to assemble an understanding of where TENORM wastes are from, what’s in them, and the risks they present to people and the environment.
  • Working with other organizations that are also confronting the problem, including states, tribes, other federal agencies, industries, environmental groups and international organizations.

Many of the materials that are considered TENORM have only trace amounts of radioactivity and are part of our everyday landscape. However, some TENORM has relatively higher concentrations of radionuclides that can result in elevated exposures to radiation. EPA is investigating TENORM and its management because it can be a hazard to human health and the environment.

All definitions referenced on this page are taken from the EPA combined report, Technologically Enhanced Naturally Occurring Radioactive Materials From Uranium Mining, Volume 1: Mining and Reclamation Background, and Volume 2: Investigation of Potential Health, Geographic, and Environmental Issues of Abandoned Uranium Mines.

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