Effect of Formaldehyde on the Upper Respiratory Tract Normal Flora of Humans and Rabbits

Background: Formaldehyde is a chemical that is used to fix a tissue after death or removal from the body to prevent autolysis and putrefaction. Exposure to formaldehyde can occur as a result of occupation. Objective: To determine the effect of the formaldehyde on the throat and nasal flora of upper respiratory tract of rabbits and humans were examined in this study. Materials and Methods: This study was conducted in the College of Health Sciences (Mercyland campus) and Teaching Hospital of Ladoke Akintola University of Technology, Osogbo. Ten rabbits and 25 human subjects were used. Throat and nasal swabs were taken from these rabbits exposed to different concentrations of formaldehyde and human subjects exposed to formaldehyde as a result of occupational exposure and non exposed individuals. Bacterial count was done using Miles and Mistral method. Microbial culture was done using the traditional cultural techniques. Results: Culture yielded growth of different species of microorganisms, majority of which were bacterial species. Bacterial counts showed reductions both in normal flora of upper respiratory tract of rabbits and humans. The reduction in the normal flora of humans was found to be statistically significant. While reduction in the normal flora of rabbits was significant when compared between controls and those exposed to 10% formaldehyde, but were not significant between controls and those exposed to 100% formaldehyde. Conclusion: This study concluded that there was significant reduction in the normal flora of humans and rabbits exposed to formaldehyde compared to non-exposed humans and rabbits.