Naturally Occurring Radioactive Materials (NORM)
An entirely natural part of the Earth, the majority of NORM radionuclides (primarily radon and radium) are a decay product of uranium and thorium.
Exposure to radon in homes, buildings, structures, etc. can reach very high, hazardous levels, as the gas accumulates non-stop.
Technologically Enhanced Naturally Occurring Radioactive Materials (TENORM)
"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".
TENORM increases your chances for exposure to NORM. In other words, "TE" ("technologically enhance") is the concentration and further alteration of radioactive materials' radiological, physical, and chemical properties through their processing, beneficiation, or disturbance.
NORM, TENORM, and Radon
Radon is an invisible, tasteless, odorless, and cancer-inducing radioactive gas that occurs naturally in the environment - Naturally Occurring Radioactive Material (NORM) - as a decay product of uranium and thorium. Discovered by the English physicist Ernest Rutherford and German physicist Friedrich Ernst Dorn at the turn of the 20th century, radon is most often found in rock, soil, and well water, and easily penetrates paper, leather, low-density plastics, paints, building materials, concrete, mortar, tar paper, wood paneling, insulation, and more.