The effects of ethylene-dibromide (106934) (EDB) on workers exposed by spraying were investigated. Blood samples were drawn from 14 sprayers in May, 1983 and July, 1983, before and after exposure. Full shift and short term personal samples were collected using charcoal tubes. Blood cultures for sister chromatid exchanges (SCE) and chromosomal aberrations were initiated within 24 hours. Seven cultures were established per person; four were used for chromosomal aberration studies and three were used for SCE analysis. At the termination of the culture, cells were harvested, fixed, stained, and scored. Analysis was also conducted using the number of high frequency cells as the dependent variable. The time weighted average for an 8 hour shift was 60 parts per million EDB. Duration of exposure to EDB had no statistically significant effect on the frequency of SCE. When the number of high frequency cells was used as the dependent variable instead of the frequency of SCE, there was no change in the results. There was no effect of duration of EDB exposure on the percentage of chromosomal aberrations. There was no significant difference before or after exposure. No cytogenetic effects due to exposure to EDB were found.