Ž . Mutation Research 446 1999 23–34 www.elsevier.comrlocatergentox Community address: www.elsevier.comrlocatermutres Genotoxicity and radioresistance in electroplating workers exposed to chromium A. Vaglenov a,b , M. Nosko c , R. Georgieva d , E. Carbonell b , A. Creus b , R. Marcos b, ) a National Centre of Radiobiology and Radiation Protection, Boul. Kliment Ohridski 132, 1756 Sofia, Bulgaria b Grup de Mutagenesi, Unitat de Genetica, Departament de Genetica i de Microbiologia, Edifici Cn, UniÕersitat Autonoma de Barcelona, ` ` ` ` ( ) 08193 Bellaterra Cerdanyola del Valles , Barcelona, Spain ` c Department of Hygiene and Occupational Diseases, Medical UniÕersity, Boul. D. NestoroÕ 15, 1431 Sofia, Bulgaria d National Centre of Hygiene, Medical Ecology and Nutrition, Boul. D. NestoroÕ 15, 1431 Sofia, Bulgaria Received 27 May 1999; received in revised form 14 July 1999; accepted 21 July 1999 Abstract A biomonitoring study was carried out to investigate the genetic risk associated to occupational exposure to chromium. Ž . The induction of genetic damage was measured by analysing the frequency of micronuclei MN in peripheral blood lymphocytes. In addition to the 40 electroplater exposed workers who participated in the study, a group constituted by 18 volunteer donors, without exposure to chromium, was analysed as a control group. Measures of chromium levels at working place and in erythrocytes and urine were obtained, as indicators of exposure. The results from this study indicate that the blood from exposed workers contained higher levels of chromium, when compared with those obtained in the control group, and that a significant increase in the frequency of both the total number of MN and the number of binucleated cells carrying Ž . MN BNMN was detected. Furthermore, a good direct relationship was obtained between the amount of chromium present in air, erythrocytes or urine and the frequency of MN. To determine the existence of radioresistance as consequence of chromium exposure, the response of lymphocytes to the in vitro g-radiation was studied. The results of this experiment show a lower induction in the increase of the frequency of MN after challenge irradiation in the lymphocytes of chromium exposed workers, which should be indicative of an adaptive response. q 1999 Elsevier Science B.V. All rights reserved. Keywords: Hexavalent chromium; Electroplating workers; Micronucleus assay; Genotoxicity; Adaptive response 1. Introduction The genotoxic effects of chromium compounds have been extensively studied by using different biological systems and genetic endpoints, as re- ) Corresponding author. Tel.: q34-93-581-20-52; fax: q34- 93-581-23-87; E-mail: rmd@cc.uab.es wx viewed by De Flora et al. 1 . Nevertheless, the different adverse health effects linked with its expo- sure, as well as the diverse cellular and molecular effects, makes the study of chromium toxicity, geno- toxicity and carcinogenicity very interesting and wx complex 2 . Exposure to chromium compounds is of special concern in many industries including primary pro- 1383-5718r99r$ - see front matter q 1999 Elsevier Science B.V. All rights reserved. Ž . PII: S1383-5718 99 00145-X