The Effects of Passive Smoking on Laryngeal and Tracheal Mucosa in Male Wistar Rats During Growth: An Experimental Study

Cigarettes contain toxic and carcinogenic substances. In this context, cigarette smoking, and similar activities, are associated with numerous pathologies, being considered a risk factor in up to 10% of the total number of deaths in adults. Recent evidence suggests that the exposure of children to smoking in the early days of their development causes many diseases. Using light microscopy, this study aims to analyze the possible histopathological effects of an experimental model of chronic inhalation of cigarette smoke (passive smoking) on the laryngeal and tracheal mucosa of young Wistar rats. A total of 24 young Wistar rats were studied for a period of 120 days. The animals were divided into two groups: passive smoking (n = 16) and control (n = 8). The level of exposure to cigarette smoke was evaluated from the urinary cotinine level. Although no cancerous lesions were identified, histopathological analysis in the laryngeal and tracheal mucosa of all the animals in the experimental group showed that the proportion of moderate and focal inflammation was higher in animals exposed to chronic inhalation of cigarette smoke (P = 0.041). Histopathologic analysis revealed moderate and focal inflammatory lesions in the region of the infraglottic mucosa in exposed animals, although without dysplastic or neoplastic lesions in the laryngeal and tracheal mucosa.