Differences in Nasopharyngeal and Lung Histopathology in Wistar Rats (Rattus norvegicus) Given Inhaled Formaldehyde Exposure with Doses of 20, 30, and 40 ppm

Abstract

Background: Formaldehyde is known as a chemical substance that may induce structural cell changes in several organs, especially the respiratory system. Different concentrations of exposure may result in different degrees of severity in histopathology.

Materials and Methods: Twenty male Wistar rats were divided into 4 groups. Inhalation of 10% formaldehyde exposure for 6 hours per day over 16 weeks was conducted. Nasopharyngeal and lung tissues were collected and stained with hematoxylin-eosin (H&E) to observe histopathological structural changes and assess the degree of severity. Bivariate analysis was performed to calculate correlation coefficients.

Results: This experimental study found that severe dysplasia is correlated with prolonged exposure. A strong correlation was found between formaldehyde concentrations and dysplasia (r=0.682), and a moderate correlation between duration of exposure and dysplasia (r=0.488).

Conclusion: The severity of dysplasia in rats aligns with both the duration and concentrations of formaldehyde exposure. Prolonged exposure increases the severity of dysplasia, as does exposure to higher concentrations of formaldehyde.