Chromosomal aberrations and micronuclei in lymphocytes in relation to alkylation of hemoglobin in workers exposed to ethylene oxide and propylene oxide.

Chromosomal aberrations and micronuclei in lymphocytes were measured in workers exposed to propylene oxide in a factory producing alkylated starch, and in workers exposed to ethylene oxide in connection with sterilization of medical equipment. Adduct levels in hemoglobin were determined as a measure of in vivo doses of the two compounds. The levels of hydroxypropylvaline in propylene oxide-exposed workers were correlated in estimated exposure doses. The levels of this adduct in the unexposed group were close to the detection limit of the method. The levels of hydroxyethylvaline, recorded in the propylene oxide-exposed group were consistent with earlier data on hemoglobin alkylation in occupationally unexposed subjects. The adduct measurements revealed increased levels of hydroxyethylvaline in the two subgroups of ethylene oxide-exposed workers, i.e., assemblers with a low and sterilizers with a high exposure. According to expectation the subgroups differed in adduct levels. The results of the cytogenetic study showed that the clastogenic potency of propylene oxide was lower than that of ethylene oxide, since the propylene oxide-exposed individuals had lower frequencies of micronuclei and chromosomal breaks compared to the assemblers despite a lower adduct level in the last group.