DNA adducts in granulocytes of hospital workers exposed to ethylene oxide.
Yong-LC; Schulte-PA; Kao-CY; Giese-RW; Boeniger-MF; Strauss-GH; Petersen-MR; Wiencke-JK
Am J Ind Med 2007 Apr; 50(4):293-302
Background: Ethylene oxide (EtO), an important industrial chemical intermediate and sterilant, is classified as a human carcinogen. Occupational EtO exposure in many countries is regulated at 1 ppm (8-hr TWA), but levels of EtO-DNA adducts in humans with low occupational EtO exposures have not been reported. Methods We examined the formation of N7-(2'-hydroxyethyl)guanine (N7-HEG), a major DNA adduct of EtO, in 58 EtO-exposed sterilizer operators and six nonexposed workers from ten hospitals. N7-HEG was quantified in granulocyte DNA (0.1-11.5 mu/gr) by a highly sensitive and specific gas chromatography-electron capture-mass spectrometry method. Cumulative exposure to EtO (ppm-hour) was estimated during the 4-month period before the collection of blood samples. Results: There was considerable inter-individual variability in the levels of N7-HEG with a range of 1.6-241.3 adducts/10(7)nucleotides. The mean levels in the nonexposed, low (< or equal to 32 ppm-hour), and high (>32 ppm-hour) EtO-exposure groups were 3.8, 16.3, and 20.3 adducts/107 nucleotides, respectively, after the adjustment for cigarette smoking and other potential confounders, but the differences were not statistically significant. Conclusions: This study has demonstrated for the first time, detectable levels of N7-HEG adducts in granulocytes of hospital workers with EtO exposures at levels less than the current U.S. standard of 1 ppm (8-hr TWA). A nonsignificant increase in adduct levels with increasing EtO exposure indicates that further studies of EtO-exposed workers are needed to clarify the relationship between EtO exposure and N7-HEG adduct formation.
Chemical-reactions; Ethylenes; Humans; Carcinogenesis; Carcinogenicity; Carcinogens; Gene-mutation; Genetic-factors
Lee C. Yong, Industrywide Studies Branch, Division of Surveillance, Hazard Evaluations and Field Studies, National Institute for Occupational Safety and Health (NIOSH), 4676 Columbia Parkway, Mail Stop R-15, Cincinnati, OH 45226
American Journal of Industrial Medicine