Thinking about returning to the office? While many businesses have implemented new ‘cleaning’ protocol, design to add surface disinfection for the treatment of inanimate objects, such as computer keyboards and telephones, the effectiveness of these regimes has been called into question by a new study
To assess the hygienic status of the typical office environ, the company Fasthosts teamed up with microbiologist Dr. Jonathan Cox (of Aston University, Birmingham, U.K). This led to a series of swabs being taken from within offices. To contextualize the data the swab results from the office were compared with other areas (often areas considered to be more typically ‘dirty’).
The headline grabbing datum is that the typical desk is around three-times dirtier than a toilet seat as well as the everyday kitchen waste bin.
For the analysis, direct microbiological counting was not undertaken. Instead, adenosine triphosphate (ATP, the energy-carrying molecule used in cells) swabs were used and the results are expressed in terms of relative light units (RTU). This enables a comparative assessment to be made in relation to the remnants of living and dead microorganisms. While the method does not provide a direct assessment, and the limitations of swabbing are well-known, the comparative aspect of the data still remains valid and this type of approach is commonly used in the food sector.
The computer keyboard record an RLU score of 383, which is above the lid of a kitchen bin, at 392. The highest recording areas were:
- Desk – RLU score of 606
- Kitchen Bin- RLU score of 392
- Keyboard – RLU score of 382
- Desk chair – RLU score of 310
- Computer mouse – RLU score of 260
- Toilet seat – RLU score of 209
- Door mat – RLU score of 209
These data emphasize the importance of good hygienic practices, such as handwashing, and they also point to the importance of regular office space disinfection, especially for shared offices where hot-desking is a common practice.
A reason given by Dr. Cox for the office items recording high scores is due to the presence of moisture, with moisture transferred from the fingertips onto your keyboard. Water is an essential component for microbial life, along with a carbon source and other nutrients.
While the levels of microorganisms vary, the study did not assess the types of microorganisms present. It may be, for example, that the higher numbers of office bacteria are human skin residents, whereas the kitchen organisms may represent organisms of a pathogenic nature. Hence a degree of caution is always required with these types of analyses.
Furthermore, the method deployed – ATP tests – are not able to test for whether viruses are still on a surface. This means the results do not inform about the probability of the SARS-CoV-2 virus surviving.
