EFFECTS OF NITROGEN-OXIDES ON NATURAL-KILLER-CELLS IN GLASS CRAFTSMENAND BRAZIERS

Objectives-To assess the effect of exposure to nitrogen oxides on peri pheral blood natural killer cells. Methods-Groups of glass craftsmen a nd braziers exposed to nitrogen oxides and non-exposed controls were s tudied. Air concentrations of nitrogen oxides were measured. Mononucle ar cells isolated from peripheral blood samples were assayed for natur al killer cell activity with K562 target cells in a Cr-51 release assa y and the percentage of natural killer cells (CD16) was measured by fl ow cytometry. Results-Braziers were exposed to 1.2 ppm nitrogen dioxid e and 8.6 ppm nitric oxide and glass craftsmen to 2.9ppm nitrogen diox ide and 26.5ppm nitric oxide. The natural killer cell activity of expo sed workers was significantly lower than in non-exposed controls (P < 0.05 ANOVA Scheffe test). The percentage of natural killer cells in gl ass craftsmen was significantly greater than in controls (P < 0.05 ANO VA Scheffe test). Regression of natural killer cell activity against a ge, smoking habit, number of years worked and current exposure to nitr ogen dioxide and nitric oxide gases was not significant. The percentag e of natural killer cells was not significantly correlated with age, s moking habit, or numbers of years worked, but was significantly relate d to air concentrations of nitrogen dioxide (P < 0.01) and nitric oxid e (P < 0.001). Conclusion-Natural killer cell activity and the percent age of natural killer cells in peripheral blood cells were altered in workers exposed to nitrogen oxides.