[An observation of the effect of sulfur dioxide on rat nasal mucosa].

This paper reports the effect of SO2 on rat nasal mucosa. The rats were forced to inhale SO2 and the effect on the nasal mucosa observed. The rats were divided into four groups. The first group inhaled 10ppm SO2; the second group 20ppm; the third group 40 ppm and the fourth group served as control. The observation lasted for 6 months. It was found that the nasal mucosa in the control group remained columnar ciliated. In the experimental groups, during the early stage (groups I, II) of exposure, there was no significant morphological change in epithelium. Then (groups I, II) the epithelium changed into cuboidal with complete disappearance of cilia, only some short and slender microvilli remained. While in the late stage (group III), the epithelium had transformed into squamous stratified and the amount of mucosal glands reduced.