Exposure to naturally occurring radiation is responsible for the majority of an average person’s yearly radiation dose (see also Nuclear Radiation and Health Effects paper) and is therefore not usually considered of any special health or safety significance.However certain industries handle significant quantities of NORM, which usually ends up in their waste streams, or in the case of uranium mining, the tailings dam.It is found in many foodstuffs (bananas for example), and indeed fills an important dietary requirement, ending up in our bones.

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The term NORM exists also to distinguish ‘natural radioactive material’ from anthropogenic sources of radioactive material, such as those produced by nuclear power and used in nuclear medicine, where incidentally the radioactive properties of a material maybe what make it useful.

However from the perspective of radiation doses to people, such a distinction is completely arbitrary.

It beta decays, mostly to calcium-40, and forms 0.012% of natural potassium which is otherwise made up of stable K-39 and K-41.

Potassium is the seventh most abundant element in the Earth’s crust, and K-40 averages 850 Bq/kg there.

Over time, as potential NORM hazards have been identified, these industries have increasingly become subject to monitoring and regulation.

However, there is as yet little consistency in NORM regulations among industries and countries.For most human activities involving minerals and raw materials, the levels of exposure to these radionuclides are not significantly greater than normal background levels and are not of concern for radiation protection.However, certain work activities can give rise to significantly enhanced exposures that may need to be controlled by regulation.The acronym TENORM, or technologically enhanced NORM, is often used to refer to those materials where the amount of radioactivity has actually been increased or concentrated as a result of industrial processes.This paper addresses some of these industrial sources, and for simplicity the term NORM will be used throughout.Table 1: Radiological characteristics of cosmogenic NORM NORM and cosmic radiation account for over 85% of an ‘average individual’s’ radiation exposure.