title: Histopathological changes of vocal folds induced by chronic pollutant exposure: an experimental study.
abstract: 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.
authors.affiliation: 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.
authors.forename: Fabiana Carla
authors.initials: FC
authors.lastname: Marcelino
authors.forename: Denise Tostes
authors.initials: DT
authors.lastname: Oliveira
mesh_terms: D000393:Air Pollutants / Q000009:adverse effects*; D000397:Air Pollution / Q000009:adverse effects*; D000818:Animals; D002119:Calcium Carbonate / Q000009:adverse effects*; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D014827:Vocal Cords / Q000187:drug effects* / Q000473:pathology; D014833:Voice Quality / Q000187:drug effects*
chemical_list: D000393:Air Pollutants; D002119:Calcium Carbonate