Cytogenetic studies in humans after short-term exposure to ethylene dibromide

Ethylene dibromide (EDB) has been shown to increase sister chromatid exchange in animal cells in vitro, but its cytogenetic effects in humans have not been previously studied. A solution containing EDB is used in the summer months in Colorado to spray felled pine trees to kill pine beetles. We have assessed the frequencies of sister chromatid exchanges and chromosomal aberrations in the peripheral blood lymphocytes of 14 sprayers both before and after exposure. Six nonexposed individuals also were tested. Full-shift personal breathing-zone air samples indicated that the sprayers were exposed to an average of 60 ppb of EDB, as an eight-hour time weighted average. The range of exposure was from 5 to 281 ppb. Workers sprayed EDB for only five to 26 days during the summer, with an average of 14 days. After adjusting for smoking and the use of prescription medicine, there was no statistically significant difference between the frequencies of either sister chromatid exchange or chromosomal aberrations before and after spraying.