The cytogenetic analysis of structural chromosome aberrations was performed in 8,000 cells from the 40 exposed workers. The data on chromosomal aberrations are given in Table 1. Aberrations produced by the pesticides included gaps, chromatid breaks, isochromatid breaks and exchanges like dicentric, rings and trivalents. The results were compared with those obtained from 30 unexposed healthy controls, who were living in the same communities, as shown in Table 2. When the corresponding data were compared between workers and controls, the workers showed significantly (p <0.05-p <0.01) higher rates for numbers of abnormal cells, gaps, chromatid breaks and chromosomal aberrations analyzed separately or combined as compared with the controls in both smokers and non smokers (Table 3). In individuals exposed to pesticides, a slight increase (but not significant) (p >0.05) in the frequency of abnormal cell, gaps and chromatid interchanges was observed in the smokers when compared to non smokers.