Immunological disturbances in anaesthetic personnel chronically exposed to high occupational concentrations of nitrous oxide and halothane.

Immunological changes in anaesthetic personnel exposed to occupational concentrations of holothane and nitrous oxide 10-60 times greater than the advised maximum were studied during routine work and after 3-4 weeks holiday. Red cell count, haemoglobin concentration and haematocrit decreased during exposure although not significantly, in comparison with a control group, but all had increased significantly after the holidays. Other changes were altered neutrophils and lymphocyte counts. Basophils disappeared from the blood during the exposure. Monocytes were not affected during the exposure, but increased after its cessation. Percentages of CD2 and CD4 lymphocytes increased significantly, but numbers of cells in T lymphocyte subpopulations (total, helper and cytotoxic/suppressor lymphocytes) were not significantly altered. B lymphocytes were most strongly affected: they decreased during working periods and did not recover after holidays. Natural killer (NK) cells, on the other hand, decreased significantly during exposure, but fully recovered during holidays. After stimulation with mitogens, phytohaemaglutin, concanavalin A, and pokeweed, lymphocytes from exposed personnel incorporated significantly more 3H-thymidine than those from control subjects, but stimulation indices did not differ. The natural killer-cell activity, serum Ig concentrations and phagocytosis by granulocytes were not altered.