Fabiana Carla Marcelino1, Denise Tostes Oliveira. 1. Department of Speech Pathology, Bauru School of Dentistry, University of São Paulo, Alameda Octavio Pinheiro Brisolla, 9-75 CEP 17012-901, Bauru, São Paulo, Brazil.
Abstract
UNLABELLED: Calcium carbonate (CaCO(3)) 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 CaCO(3) inhalation, respectively, during 15, 30, and 90 days. Then, the larynx region was dissected and embedded in paraffin, and 5-mum 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 CaCO(3) inhalation. CONCLUSIONS: This study suggests that the inhalation of pollutant particles, such as CaCO(3), induces inflammatory alterations in the larynx; this can affect the vibration of the vocal folds, which influence vocal function.
UNLABELLED: Calcium carbonate (CaCO(3)) 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 CaCO(3) inhalation, respectively, during 15, 30, and 90 days. Then, the larynx region was dissected and embedded in paraffin, and 5-mum 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 CaCO(3) inhalation. CONCLUSIONS: This study suggests that the inhalation of pollutant particles, such as CaCO(3), induces inflammatory alterations in the larynx; this can affect the vibration of the vocal folds, which influence vocal function.