Surface exposure dating with cosmogenic nuclides Free text chat no sign ups
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.Table 1: Radiological characteristics of cosmogenic NORM NORM and cosmic radiation account for over 85% of an ‘average individual’s’ radiation exposure.Most of the balance is from exposure related to medical procedures.Excluding uranium mining and all associated fuel cycle activities, industries known to have NORM issues include: Another NORM issue relates to radon exposure in homes, particularly those built on granitic ground.Occupational health issues include the exposure of flight crew to higher levels of cosmic radiation, the exposure of tour guides to radon in caves, exposure of miners to radon underground, and exposure of workers in the oil & gas and mineral sands industries to elevated radiation levels in the materials they handle.
However from the perspective of radiation doses to people, such a distinction is completely arbitrary.All minerals and raw materials contain radionuclides of natural origin.The most important for the purposes of radiation protection are the radionuclides in the U-238 and Th-232 decay series.At higher altitudes, the dose due to both increases, meaning that mountain dwellers and frequent flyers are exposed to higher doses than others.
For most people, cosmogenic NORM barely contributes to dose – perhaps a few tens of microsieverts per year.
Material giving rise to these enhanced exposures has become known as naturally occurring radioactive material (NORM).