Fundamental and Molecular Mechanisms of Mutagenesis zyxwvuts ELSEVIER Mutation Research 327 (1995) 33-39 Intercomparison in cytogenetic dosimetry among five laboratories from Latin America Omar F. Garcia a, Adriana T. Ramalho b,*, Marina Di Giorgio ‘, Sylvia S. Mir d, Marco E. Espinoza e, J. Manzano a, N. Nasazzi ‘, I. Lopez d a zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA Secretaria Ejecutiua para Asuntos Nucleares (SEAN-CPHR), 18A, 4110, esq. 43, Playa, Ciudad Habana, Cuba b lnstituto de Radioprote@o e Dosimetria, Comissio National de Energia Nuclear, Au. Sahlador Allende, Barra da Tijuca, CP 37750, Rio de Janeiro, Brazil ’ Gerencia Seguridad Radioldgica y Nuclear, Comisidn National de Energia Atomica, Aereopuerto Ezeiza, casilla de correo 40, CP 1802, Buenos Aires, Argentina ’ Comisi& Chilena de Energia Nuclear, Casilla 188-0, Santiago, Chile e Institute Peruano de Energia Nuclear, zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIH ALL Canada 1470, Lima 41, Peru Received 15 June 1994; revision received 20 July 1994; accepted 27 July 1994 zyxwvutsrqponmlkjihgfedcbaZY Abstract As part of a regional International Atomic Energy Agency (IAEA) collaborative project within Latin America, five countries participated in an intercomparison in cytogenetic dosimetry. Coded slides for chromosomal aberra- tions and micronucleus analyses were prepared by the coordinator laboratory which organized the exercise and sent to the other participating laboratories. For estimates of dose, each laboratory scored the frequency of dicentrics in metaphases and the frequency of micronuclei in binucleated cells. The lymphocytes were irradiated with 6oCo -y-rays (0, 0.75, 1.5 and 3.0 Gy). Eleven of the 15 estimates of dose based on dicentrics and nine of the 12 based on micronuclei fell within +30% of the true dose. When considering the uncertainties of the dose estimates, the true dose fell within the 95% confidence limits of the estimates on eight of the 15 occasions for dicentrics and four of the 12 for micronuclei. Ke>+vor& Chromosomal aberration scoring; Cytogenetic dosimetry; Interlaboratory comparison 1. Introduction The ARCAL program (Regional Collaboration for Nuclear Science and Technology Develop- ment within Latin America) was established with * Corresponding author. support of the International Atomic Energy Agency (IAEA) with the purpose of collaboration among the regional countries in subjects of com- mon interest. One of these is the project AR- CAL-l (Radiological Protection). As part of its planning for the period 1990-1992 an intercom- parison in cytogenetic dosimetry was organized in which five laboratories from different countries participated. 0027-5107/95/$09.50 0 1995 Elsevier Science B.V. All rights reserved SSDI 0027-5107(94)00066-2