Absence of signs of vitamin B12--nitrous oxide interaction in operating theatre personnel.

Inactivation of vitamin B12 by nitrous oxide leads to megaloblastic haematopoiesis. Peripheral blood counts and films, serum vitamin B12 and plasma and erythrocyte folate concentrations were studied in eight anaesthetists and seven internists to find if the interaction is an occupational health hazard to operating theatre personnel chronically exposed to trace concentrations of nitrous oxide. In addition, blood counts were studied in two retrospective materials of 118 operating theatre nurses working in scavenged operating theatres and in ten subjects working in unscavenged theatres. No definite signs of B12-nitrous oxide interaction could be observed in the peripheral blood samples from these persons.