AMBIENT AND BIOCHEMICAL EFFECT MONITORING OF WORKERS EXPOSED TO ETHYLENE-OXIDE

Objectives: Ethylene oxide is an alkylating agent known to be a direct ly acting mutagen and carcinogen. This study describes the relationshi p between workplace ambient air concentrations of ethylene oxide and t he concentration of N-2-hydroxyethylvaline in the globin of exposed wo rkers. Methods: During the sterilization of medical equipment, 12 work ers were occupationally exposed to ethylene oxide. personal and statio nary ambient air measurements were carried out to monitor the external exposure. The determination of the protein adducts was based on the N -alkyl-Edman method, introducing a new commercially available dipeptid e standard for calibration purposes. Results: Ethylene oxide concentra tions ranging from 0.2 to 8.5 ppm were found in the workplace air. The adduct concentrations ranged from 5,219 to 32,738 pmol N-2-hydroxyeth ylvaline/g globin in the case of regularly exposed workers(n = 9) and from 518 to 3,321 pmol N-2-hydroxyethylvaline/g globin for three perso ns with occasional contact with ethylene oxide. Conclusions: The Deuts che Forschungsgemeinschaft established in 1993 a relationship between the ethylene oxide concentration in ambient air and the amount of N-2- hydroxyethylvaline in human globin. By extrapolation, constant exposur e to 1 ppm ethylene oxide should yield approximately 4,000 pmol N-2-hy droxyethylvaline/g globin. The ambient air concentrations of ethylene oxide and the amount of N-2-hydroxyethylvaline determined within the p resent study confirm this extrapolation in practice. In addition, the determination of adducts based on the use of commercially available di peptide standards for calibration purposes turned out to be an advanta geous alternative to the commonly used protein standards.