Radioelement mapping

A high quality geochemical database is pertinent to a wide range of investigations in the earth and life sciences, and should be considered as an essential component of environmental knowledge. Natural radioactive elements associated with radioactive raw materials, the radiation environment and their health impact, form part of such a comprehensive geochemical database. Databases on radioelement mapping have been increasingly used and updated in several countries for the exploration of uranium and thorium raw materials for nuclear fuels, environmental geochemical studies and the assessment of the radiation environment. The demand for radioelement databases is expected to grow over the next decade as new applications for them are foreseen. To this end, the IAEA invited a group of experts to investigate the issues and draft a report on the current state of radioelement mapping and the development of a global radioelement baseline. In the past, based on gamma surveys for uranium exploration and field gamma spectrometry, the IAEA took a leading role in facilitating the development of methodologies and standards for the quantitative estimation of radioelement concentrations and for the geochemical mapping of radioelements.. The need for approved methodologies and standards for radioelement mapping was identified at an IAEA panel meeting in 1972. This led to IAEA technical meetings in 1973 and 1974 and the publication of the proceedings of an IAEA symposium entitled Exploration for Uranium Ore Deposits. In subsequent years, calibration standards and procedures were developed for radiometric field equipment. The standards were based on geological reference materials for laboratory gamma ray spectrometers issued by the IAEA. The information on the standards and the equipment has been documented in detail in IAEA technical reports: Preparation and Certification of IAEA Gamma ray Spectrometry Reference Materials RGU-1, RGTh-1 and RGK-1, report IAEA/RL/148 (1987); and Construction and Use of Calibration Facilities for Radiometric Field Equipment, Technical Reports Series No. 309 (1989). This report should be read in combination with other IAEA reports which describe the use of uranium exploration data and techniques applied to the preparation of radioelement maps and the establishment of guidelines for radioelement mapping using gamma ray spectrometry. It is also recommended that this report be read in combination with the UNESCO Final Report of the International Geological Correlation Programme Project 259. That report analysed methods and inconsistencies in geochemical mapping and specified the requirements for a global geochemical database. Specifically, the report recommended the establishment of a global geochemical database for environmental and resource management. In addition, gamma ray spectrometry was introduced as a fundamental method for radioelement mapping