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. NORM sources In 2007, China National Nuclear Corp (CNNC) commissioned Sparton Resources of Canada with the Beijing No.5 Testing Institute to undertake advanced trials on leaching uranium from coal ash in central Yunnan. In early 2007, Sparton signed an agreement with the Xiaolongtang Guodian Power Company of Yunnan for a program to test and possibly commercialize the extraction of uranium from waste coal ash. Some 250 km southwest of Kunming, the Xiaolongtang, Dalongtang and the Kaiyuan power stations, all located within 20 km of each other burn coal from a centrally located open pit lignite mine with high ash content (20-30%) and very high uranium content. The coal uranium content varies from about 20 to 315 ppm and averages about 65 ppm. The ash averages about 210 ppm U (0.021%U) - above the cut-off level for some uranium mines. The power station ash heap contains over 1000 tU, with annual arisings of 190 tU. (Recovery of this by acid leaching is about 70%.) The main radionuclide in scrap from the oil and gas industry is radium-226, with a half-life of 1600 years as it decays to radon. Those in nuclear industry scrap are cobalt-60 and caesium-137, with much shorter half-lives. Application of a 0.3 mSv/yr dose limit results in a clearance level for Ra-226 of 500 Bq/kg for oil/gas scrap, compared with 10 Bq/kg for nuclear material. During mining and milling of zircon, care must be taken to keep dust levels down. Then when zircon is fused in refractories or ceramics manufacture, silica dust and fumes must be collected. This may contain the more volatile radionuclides, Pb-210 and Po-210, and the collection of these gases means that pipeworks and filters become contaminated. The main radiological issue is occupational exposure to these radionuclides in airborne dusts in the processing plant. Waste produced during zirconia/zirconium production can be high in Ra-226, which presents a gamma hazard, and waste must be stored in metal containers in special repositories. Powders from filters used during zirconia manufacture have been assayed as high as 200,000Bq/kg of Pb-210 and 600,000 Bq/kg Po-210. Tin production Radon exposure is often an issue in metal mines, and a survey of 25 underground mines in China showed six having radon concentrations of over the control limit of 1000 Bq/m 3. In all the metal mines the annual average effective dose from radon and radon progeny was 7.75 mSv. Mineral sands

Cosmogenic NORM is formed as a result of interactions between certain gases in the Earth’s atmosphere and cosmic rays, and is only relevant to this paper due to flying being a common mode of transport. Since most cosmic radiation is deflected by the Earth’s magnetic field or absorbed by the atmosphere, very little reaches the Earth’s surface and cosmogenic radionuclides contribute more to dose at low altitudes than cosmic rays as such. 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. By contrast, terrestrial NORM – especially radon – contributes to the majority of natural dose, usually over 1000 microsieverts (1 mSv) per year. Some of the main comsogenic nuclides are shown in Table 1, carbon-14 being important for dating early human activities. Radioactive materials which occur naturally and where human activities increase the exposure of people to ionising radiation are known by the acronym 'NORM'. Another major source of terrestrial NORM is potassium 40 (K-40). The long half-life of K-40 (1.25 billion years) means that it still exists in measurable quantities today. 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. It is found in many foodstuffs (bananas for example), and indeed fills an important dietary requirement, ending up in our bones. (Humans have about 65 Bq/kg of K-40 and along with those foods are therefore correspondingly radioactive to a small degree. A 70 kg person has 4400 Bq of K-40 – and 3000 Bq of carbon-14.) Cosmogenic NORM Granite, widely used as a cladding on city buildings and also architecturally in homes, contains an average of 3 ppm (40 Bq/kg) uranium and 17 ppm (70 Bq/kg) thorium. Radiation measurements on granite surfaces can show levels similar to those from low-grade uranium mine tailings. Table 8 shows some recorded activity concentrations for building materials. However some extreme values in excess of these have also been recorded.European Commission (Directorate-General for Energy and Transport), 2003 Radiation Protection 135: Effluent and dose control from European Union NORM industries: Assessment of current situation and proposal for a harmonised Community approach, Volume 1: Main Report. Tantalum usually occurs with the chemically-similar niobium, often in tantalite and columbite, coltan (columbite + tanatalite), or polychlore (niobium). Tantalum ores, often derived from pegmatites, comprise a wide variety of more than a hundred minerals, some of which contain uranium and/or thorium. Hence the mined ore and concentrate contain both these and their decay products in their crystal lattice. Concentration of the tantalum minerals is generally by gravity methods (as with mineral sands), so the lattice-bound radioisotope impurities if present will report with the concentrate. The first hilarious title in the award-winning, laugh-out-loud series, The World of Norm. Perfect for fans of Tom Gates and Diary of a Wimpy Kid. The EU encourages the use of NORM residues in building materials, subject to dose rate from gamma exposure being below 1 mSv/yr from them. Coal ash and smelting slag are an important constituent of building materials in China. Recycling and NORM Cooper, M. B. 2005 Naturally Occurring Radioactive Materials (NORM) in Australian Industries - Review of Current Inventories and Future Generation, ERS-006, A Report prepared for the Radiation Health and Safety Advisory Council

Earlier IAEA recommendations for the classification of exempt waste ( i.e. beneath low-level, and therefore not requiring any special facilities for disposal) are between 10 Bq/g and 1 MBq/g for 'moderate amounts'– depending on the radionuclide in question and the chances of public exposure ( Radiation Protection and Safety of Radiation Sources: International Basic Safety Standards, IAEA July 2014), however in practice categorization of waste is strongly determined by where the waste comes from. Radon also occurs in natural gas at up to 37,000 Bq/m 3, but by the time it gets to consumers the radon has largely decayed. However, the solid decay products then contaminate gas processing plants, and this manifestation of NORM is an occupational health issue, as discussed above. European Commission (Directorate-General Environment, Radiation Protection) 2003, Radiation protection 132: MARINA II, Update of the MARINA Project on the radiological exposure of the European Community from radioactivity in North European marine waters Radon in homes is one occurrence of NORM which may give rise to concern and action to control it, by ventilation. 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. 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. This means that material which is considered radioactive waste in one context may not be considered so in another. Also, that which may constitute low-level waste in the nuclear industry might go entirely unregulated in another industry (see section below on recycling and NORM).Dale, L., Trace Elements in Coal, Australian Coal Association Research Program (ACARP), Report No. 2 (October 2006) In South Africa, HolGoun's Uranium and Power Project was investigating uranium recovery from the Springbok Flats coal field, estimated to contain 84,000 tU at grades of 0.06 to 0.10% U. The project is investigating the feasibility of mining the low-grade coal, using it to fire a conventional electricity generation plant, and extracting the uranium from the residual ash. NORM levels are typically expressed in one of two ways: Becquerels per kilogram (or gram) indicates level of radioactivity generally or due to a particular isotope, while parts per million (ppm) indicates the concentration of a specific radioisotope in the material. Terrestrial NORM