Uranium exploration data and global geochemical baselines: The need for co-ordinated action

Public concern about environmental problems continues. In order to assess the magnitude of potential problems it is necessary to have comprehensive information. The absence of quantitative geochemical data to map the surface composition of the earth is one of the major information gaps in present day environmental science. An IAEA Technical Committee meeting held in November 1993 reviewed the uses of uranium exploration data for environmental purposes. Most attention was focussed on data involving radiation measurements. Uranium exploration programmes conducted since 1970 in many countries collected a considerable amount of geochemical survey data, providing information about the distribution of non-radioactive elements in the natural environment. Canada is one of several countries where such data provided the foundation for national geochemical mapping; other countries could benefit from similar actions. Increasing importance is being attached by governments to the need to enact effective environmental legislation concerning ''safe levels'' of many chemical substances. Such legislation requires geochemical variations in the natural environment. It is becoming necessary to make quantitative comparisons of element abundances across national boundaries, and from continent to continent. In 1995 the IAEA, with other organizations, supported UNESCO to publish a report concerned with the establishment of a Global Geochemical Reference Network. This is designed to provide a framework to connect all types of geochemical survey, to move towards international compatibility of data. The report contains recommendations relating to the standardization of field and laboratory methods; the use of the most sensitive analytical techniques; and standardization of data management. Ground and airborne gamma ray spectrometry, and nuclear laboratory techniques are all discussed. Following the publication of the report, the International Union of Geological Sciences has now established a Working Group, on Continental Geochemical Baselines, to coordinate implementation of the recommendations in the UNESCO report. National atomic energy organizations are invited to participate