Evaluation of the antimicrobial effect of a far-uv radiation lamp in a real-life environment

Abstract

Background

Using far-Ultraviolet-C (UVC) radiation with an emission maximum of 222 nm, has the potential to kill bacteria while not being harmful to humans and can be used continuously in public areas. Elevators pose a high risk of infection transmission, as they are small, crowded spaces with poor ventilation. In such a setting continuous decontamination would be very useful. This study aimed to measure the effectiveness of a far-UVC lamp installed in a frequently used elevator by comparing the bacterial load found in that elevator with the bacterial load in a control elevator.

Methods

Microbial load was measured by different methods; ATP bioluminescence, surface samples were collected by contact slides, contact plates, and swabbing. Air samples were also collected.

Results

No significant differences were found in the microbial content between the control elevator and the UV-lamp elevator, regardless of whether the UV-lamp was always on, or was used with a motion sensor to turn off when someone entered the elevator.

Conclusions

The results suggest that the far-UVC requires a longer time to kill the bacteria, while the people traffic were continuously re-contaminating the elevators.