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

Abstract

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)