[Effects of small nitrogen compound concentrations on the upper respiratory tract]

The authors examined a group of 160 persons employed at an exposure to small concentration (below HAC) of nitrogen and ammonia oxides, and a group of 130 controls. It was found that in the group of subjects exposed to toxic compounds the percentage of persons suffering from inflammation of the upper respiratory tract was much higher (37.5%) than in the control group (13.1%). Olfactometric examinations indicated a disadvantageous effect of the mentioned compounds upon the acuity of the sense of smell, whereas rhinospirometric examination did not reveal any differences between the control group and the group of persons exposed to nitrogen and ammonia oxides.