Uncertainties in the definition of critical groups to chronic exposure scenarios

• Published in: International Congress series 2002-02, Vol.1225, p.25-31
• Main Authors: Rochedo, Elaine R.R, Amaral, Eliana C.S, Hacon, Sandra S
• Format: Article
• Language: English
• Subjects: Radioactive material; Toxic material; Uranium
• ISSN: 0531-5131; 1873-6157
• DOI: 10.1016/S0531-5131(01)00538-6

At the moment of the licensing of the uranium mining and milling installation at Poços de Caldas, MG, critical groups have been defined according to the local land and water uses by the surrounding population. It was verified that all critical groups are now, about 12 years later, different from those previously defined, mainly because of a change in the occupation pattern of a previous remote area, as infrastructure such as roads and energy became available. The same situation can be foreseen for a new uranium mining, in an area that can be presently considered as being remote, as infrastructure provided by the installation will create new opportunities in the region. There already exist in Brazil several examples related to remote degraded areas that were abandoned, containing toxic or radioactive material that turned into environmental problems or problems of public health concern. Some examples are presented, including actual and foreseen situations, showing that it is not advisable to abandon polluted areas, even those located in remote places. The difficulty is in deciding which places to intervene where investment for recovery of large areas is not justified in terms of dose or risk reduction as the land is not used by any population group. The definition of critical groups and the derivation of operational levels are not trivial tasks. Guidance in terms of individual doses and assessment methodology must be defined or procedures of uncertain analysis and long-term follow-up seem to be necessary if a certain degree of confidence on risks to members of the public is to be achieved.