Blowing in the wind: Bacteria and fungi are spreading from public restroom hand dryers

Abstract

This study aimed to identify and quantify fungi and bacteria in the airflow of restroom hand dryers in public areas. Airflow from restroom hand dryers in 8 retail locations was tested using three types of culture media, followed by PCR and sequence analysis to identify microbial species. Both bacterial and fungal colonies were detected in all locations. The number of colonies did not vary significantly across different locations, suggesting a similar level of microbial spread by hand dryers between different types of commercial stores. Molecular analysis revealed 24 bacterial species and 40 fungal species. Of these species, 48% (31/64) have been reported to be implicated in various infections in humans, primarily those with underlying medical conditions. This study is the first to demonstrate the spread of fungi by the airflow of restroom hand dryers, and the first to show the prevalence of different fungal and bacterial species spread by restroom hand dryers in common public areas.

Keywords:

• Air pollution
• bacteria
• electrical hand dryer
• fungi
• restroom

Acknowledgements

The author appreciates Dr. Li Peng and Dr. Doris Wu at the National Institutes of Health, Bethesda, Maryland, USA, for assistance with PCR and data analysis; Dr. Karl V. Clemons, Department of Medicine, Stanford University School of Medicine, Stanford, California, USA, for critical review and insightful comments to the manuscript; and Dr. Patrick R. Harrison, Department of Psychology and Neuroscience, University of North Carolina at Chapel Hill, USA, for constructive discussion and support.

Disclosure statement

No conflict of interest.

Funding

This work received no specific grant from any funding agency.