Whole-organism concentration ratios in wildlife inhabiting Australian uranium mining environments.

Wildlife concentration ratios for Ra, Pb, Po and isotopes of Th and U from soil, water, and sediments were evaluated for a range of Australian uranium mining environments. Whole-organism concentration ratios (CR) were developed for 271 radionuclide-organism pairs within the terrestrial and freshwater wildlife groups. Australian wildlife often has distinct physiological attributes, such as the lower metabolic rates of macropod marsupials as compared with placental mammals. In addition, the Australian CRs originate from tropical and semi-arid climates, rather than from the temperate-dominated climates of Europe and North America from which most (>90%) of internationally available CR values originate. When compared, the Australian and non-Australian CRs are significantly different for some wildlife categories (e.g. grasses, mammals) but not others (e.g. shrubs). Where differences exist, the Australian values were higher, suggesting that site-, or region-specific CRs should be used in detailed Australian assessments. However, in screening studies, use of the international mean values in the Wildlife Transfer Database (WTD) appears to be appropriate, as long as the values used encompass the Australian 95th percentile values. Gaps in the Australian datasets include a lack of marine parameters, and no CR data are available for freshwater phytoplankton, zooplankton, insects, insect larvae or amphibians; for terrestrial environments, there are no data for amphibians, annelids, ferns, fungi or lichens & bryophytes. The new Australian specific parameters will aide in evaluating remediation plans and ongoing operations at mining and waste sites within Australia. They have also substantially bolstered the body of U- and Th-series CR data for use internationally.