The aim of this study was to investigate, by using chromosome aberration (CA) and sister chromatid exchange (SCE) tests, whether or not the workers employed in the iskenderun (Turkey) iron and steel factory have any genotoxic risk. The CA and the SCE were investigated in 48 males employed in a coke ovens unit and 8 males employed in a product side unit of the factory and in control groups. The frequency of CA was higher while the frequency of the SCE was not in all the smoker-nonsmoker workers than in smoker-nonsmoker control groups. In addition, there was no significant decrease in the RI, while the MI was significantly lower than in the controls. (C) 2002 Wiley-Liss, Inc.