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Ore extraction and processing may lead to enhanced levels of naturally occurring radionuclides (NORs) in products, by-products and waste and in surroundings and installations of the facility. In the framework of the EC-DGXI Common Approach for REstoration of contaminated sites project (CARE) [ H. Vandenhove, A. Bousher, P. Hedemann Jensen, D. Jackson, B. Lambers, Th. Zeevaert, Investigation of a Possible Basis for a Common Approach with Regard to the Restoration of Areas Affected by Lasting Radiation Exposure as a Result of Past or Old Practice or Work Activity (CARE), EC-DG XI-project 96-ET-006, Radiation Protection 115 (EC, Luxembourg), 2000; H. Vandenhove, European Sites Contaminated by Residues from the Ore-Extracting and -Processing Industries, Proc. Int. Symp. Arlington, VA, USA, 1999, IAEA, Vienna, in preparation] information was collated on the industrial processes and the levels of NORs in parent material, waste and by-products of mentioned industries and their spreading in Europe. Nine important categories of industries were identified and discussed. The most contaminating industries are uranium mining and milling, metal mining and smelting and the phosphate industry. Radionuclide levels in products and/or waste products from the oil and gas extraction industry and of the rare earth and zirconium and ceramics industries may be particularly elevated, but waste streams are limited. Impact on the public from coal mining and power production from coal is commonly considered low. No typical values are available for contaminant levels in materials, buildings and surroundings of radium extraction and luminising plants, nor for thorium extraction and processing plants. An attempt to give an overview of sites in Europe contaminated with NORs, with emphasis on past practices, was only partly successful since information was often limited or unavailable. Extent of contamination can be possibly assessed from production figures.

The potential to phytoextract uranium (U) from a sandy soil contaminated at low levels was tested in the greenhouse. Two soils were tested: a control soil (317 Bq 238U kg-1) and the same soil washed with bicarbonate (69 Bq 238U kg-1). Ryegrass (Lolium perenne cv. Melvina), Indian mustard (Brassica juncea cv. Vitasso), and Redroot Pigweed (Amarathus retroflexus) were used as test plants.The annual removal of the soil activity with the biomass was less than 0.1%. The addition of citric acid (25 mmol kg-1) 1 week before the harvest increased U uptake up to 500-fold. With a ryegrass and mustard yield of 15000 kg ha-1 and 10000 kg ha-1, respectively, up to 3.5% and 4.6% of the soil activity could annually be removed with the biomass.With a desired activity reduction level of 1.5 and 5 for the bicarbonate washed and control soil, respectively, it would take 10 to 50 years to attain the release limit.A linear relationship between the plant 238U concentration and the 238U concentration in the soil solution of the control, bicarbonate-washed, or citric acid-treated soil points to the importance of the soil solution activity concentration in determining U uptake and hence to the importance of solubilising agents to increase plant uptake.However, citric acid addition resulted in a decreased dry weight production (all plants tested) and crop regrowth (in case of ryegrass).