DNA-protein cross-links and sister chromatid exchange frequencies in lymphocytes and hydroxyethyl mercapturic acid in urine of ethylene oxide-exposed hospital workers.

The lymphocytes of 25 hospital workers exposed to ethylene oxide and of a standardized control group were investigated for DNA damage (measured by alkaline filter elution) and sister chromatid exchange (SCE) frequencies. Additionally, the excretion of hydroxyethyl mercapturic acid (HEMA) in the 24-h urine of ten workers and ten control persons was determined. The peak levels of ethylene oxide in air during the first 8 min after opening of the sterilization unit were measured. Peak levels of ethylene oxide in the air of up to 417 ppm after opening of the sterilization unit were detected. In the alkaline filter elution assay we found significantly reduced elution rates in the exposed workers, indicating DNA-protein cross-links. The reduction of the elution rates through HVLP filters correlated significantly with the exposure classification (low, medium, high) (r = -0.45, P < 0.05) and the ethylene oxide peak level after opening of the sterilization unit (r = -0.42, P < 0.05). The SCE frequencies in the standardized control group were significantly elevated. With respect to (n = 78) historic control SCE values of our institute, the SCE values of the disinfectors were not significantly elevated (6.54 vs 6.27). The ethylene oxide-exposed workers did not have a greater percentage of high-frequency SCE cells. The mean HEMA concentration in the urine of the exposed workers was significantly elevated, but there were wide variations in HEMA concentrations and no correlation to ethylene oxide exposure. We conclude that the alkaline filter elution assay may be a sensitive parameter for ethylene oxide-exposed workers.(ABSTRACT TRUNCATED AT 250 WORDS)

[Experiences with alkaline filter elution for the detection of DNA damage by genotoxic compounds]. / Erfahrungen mit der Alkalischen Filterelution beim Nachweis von DNA-Schäden durch gentoxische Verbindungen.

In biological effect monitoring the alkaline filter elution is a suitable method to detect DNA strand breakage and cross-linking in peripheral blood lymphocytes. We applied this method to three groups of workers occupationally exposed to carcinogens: n = 39 welders with exposure to chromium and nickel, n = 20 female shoemakers with exposure to benzene and n = 25 disinfectors in hospitals with exposure to ethylene oxide. In comparison to standardised control groups our results must be interpreted as indicating an increased rate of DNA cross-linking in welders and disinfectors whereas the female shoemakers showed an increased rate of DNA strand breakage. The differences between the results of the exposed groups and the stratified control groups were significant in most cases. We could reexamine 6 shoemakers 4 months after cessation of exposure to benzene; at this moment the results were indicating a clear decrease of the DNA strand breakage. Therefore the method of alkaline filter elution seems to be a valuable tool in biological effect monitoring of groups occupationally or environmentally exposed to carcinogens, especially if the exposure is low, but persistent over a long period.