Histopathological Changes of Vocal Folds Induced by Chronic Pollutant Exposure: An Experimental Study

Calcium carbonate (CaCO3) particles, the main component of chalk, are an important pollutant in the Brazilian school environment. However, there are few reports of the effect of this pollutant in the vocal folds and its influence in voice disorder in the literature. Methods Thirty rats (Wistar), randomly divided into two groups, the control group and the experimental group, were submitted to air or to CaCO3 inhalation, respectively, during 15, 30, and 90 days. Then, the larynx region was dissected and embedded in paraffin, and 5-خ¼m sections were obtained for microscopic analysis. Results No histopathological alteration was found on the vocal folds in the control group. In the experimental group, a moderate chronic inflammatory infiltrate, characterized by macrophage cells, was found in the vocal folds after 30 and 90 days of the CaCO3 inhalation. Conclusions This study suggests that the inhalation of pollutant particles, such as CaCO3, induces inflammatory alterations in the larynx; this can affect the vibration of the vocal folds, which influence vocal function.