Nonrandom distribution of breakpoints in the karyotypes of workers occupationally exposed to benzene

The distribution of the breakpoints in the karyotypes of workers occupationally exposed to benzene was tested. Fifty-six workers exposed to benzene were investigated cytogenetically. A significant increase in chromosome aberrations was observed. The distribution of the breakpoints in the karyotypes of examined workers was significantly nonrandom (p less than or equal to 0.001). The breakpoints accumulated mainly on chromosomes 2, 4, and 7.