Sister Chromatid Exchanges In Lymphocytes Of Dentists And Chairside Assistants - No Indication Of A Mutagenic Effect Of Exposure To Waste Nitrous-Oxide

Cytogenetic methods are used increasingly for monitoring occupational exposure to potential mutagenic agents. By one such method, the sister chromatid exchange (SCE) test, previous studies of hospital operating room personnel did not indicate any mutagenic effect from exposure to waste anesthetic gases. Dentists and their assistants are exposed to much higher levels of nitrous oxide than hospital personnel, and in studies of dentists it is possible to eliminate bias from concomitant exposure to halogenated anesthetics by including unexposed persons engaged in the same professional activities as the exposed persons. SCE was examined in lymphocytes of venous blood from 38 female dentists and 74 chairside assistants, all working in the Child Dental Service, and 30 male dentists, of whom 23 worked in private practice. From studies of the model y = bo + b1 X age + b2 X cig./day + b3 X hours of exposure to nitrous oxide/week, by multiple linear regression, there was no indication of any influence of exposure to nitrous oxide on SCE. It was concluded that, from the SCE test, there is no indication of a mutagenic effect from exposure to waste nitrous oxide, and that possible health hazards from such exposure would be induced by other effects of nitrous oxide.