Does usage of a room air freshener affect the nasal mucosa?

Background: Effects of chemicals emitted from the room air freshener sprays (RAFSs) on nasal mucosa are still unclear. The purpose of this study was to investigate effects of RAFSs on the nasal mucosa of rats for different time intervals.

Methods: Twenty-eight rats were randomly divided into four experimental groups: group 1 (n = 7) was the control group and not exposed to RAFS or other chemicals, group 2 (n = 7) was exposed to RAFS for 1 month, group 3 (n = 7) was exposed to RAFS for 2 months, and group 4 (n = 7) was exposed to RAFS for 3 months. Samples from the nasal septum were stained using hematoxylin and eosin solution, examined by a pathologist using a light microscope, and analyzed with Fisher's exact test.

Results: We observed that distinct histopathological differences in the nasal mucosa of exposed rats depends on different time intervals (p < 0.05). Increased congestion was found after the 1st month of exposure (group 2). Although edema and mild inflammatory cell infiltration, including some eosinophils, was seen after the 2nd month (group 3), squamous metaplasia, numerous eosinophils, and intense inflammatory cell infiltration began after 3 months of exposure (group 4).

Conclusion: Our results showed that continuous use of RAFS can cause inflammation and eosinophilic infiltration in rats, which begins after 2 months of exposure and may lead to metaplasia after 3 months. Because of differences in body size, geometry, and physiological responses of rats, the extrapolation of these results to humans is not straightforward. However, any such comparison should be made with caution. Finally, more performance is necessary to clarify this subject.