Maltese Researcher Makes Case For Basic UV Torch To Expose COVID-Contaminated Surfaces


An independent Maltese researcher has published a scientific paper that brings to light the possible uses of UVA (ultraviolet A) rays to expose surfaces contaminated with the COVID-19 virus and other germs. Among the various forms of application, Charles Micallef, whose background is in field of public health, has shown how a basic UV flashlight can expose dirt on surfaces that appear to be perfectly clean to the naked eye.

In his paper, Micallef writes that he sought to explore “how one can detect uncleanliness using a UV flashlight. The formulated hypothesis questions several scenarios when this gadget could prove useful. Examples include: schools, workplace, childcare centres, bars, restaurants, hotels, public restrooms, hospitals, elderly homes, public transport and items like gloves and stretchers”.

Use UV light & wipe the surface clean!

Micallef, who is a fossil collector and uses UV light to determine the authenticity of fossils, thought it could be a good idea to demonstrate the uses of UV light to detect the cleanliness or otherwise of surfaces.

In the video below, he uses a UV flashlight to expose the dirt on a seemingly clean bathroom tile; he then cleans it using a wet wipe and points the UV rays towards it again to show that the dirt is gone.  

A simple, inexpensive solution?

Micallef explains that while vaccines protect us from COVID-19, that’s where the big money lies as far as the pharmaceutical industry is concerned. Something as simple and inexpensive as a UVA torch can serve as a good way to help prevent the transmission of COVID-19 and other diseases.

“This is something that already exists of course, but I wanted to bring to light something that can be so simple in its application. A UV torch can be purchased from the internet for about Є16 and it can help expose contaminated surfaces. Think about the amount of dirt in surfaces in cinemas or in hotel rooms, for instance. That can be exposed, and then properly cleaned, using a simple UV flashlight.”

Wouldn’t the use of such flashlights make everyone completely obsessed? Micallef says that his intention is not for UV lights to be used in people’s homes, but rather in public places such as restaurants, toilets, schools, hospitals etc.

Limitations & safety concerns

What about limitations? Micallef writes that the most basic limitation is related to visibility – the dimmer the surrounding light is, the more the unclean areas become visible. Another small issue lies with the fact that surfaces may need to be rinsed from any soap or detergent residues, but the “gadget still remains a valid tool to check whether cleaning protocols are adhered to especially in areas that could potentially be contaminated with germs”.

While acknowledging that further studies would be required for the proper application of his solution, Micallef also mentions another drawback attributed to the safety of UVA, but writes that “a UV flashlight used responsibly can form an integral part of the arsenal for the visual monitoring of cleaning completion on high touch surfaces to curb the COVID pandemic by slowing the spread of this infectious disease”.

On safety-related concerns, he writes: “Sunlight consists of two types of harmful rays: long wave UVA and short wave UVB. UVA rays are less intense than UVB but long term exposure can still cause cancer and eye damage. As UV flashlights usually emit wavelengths between 365nm and 395nm that is, within the UVA range, they can be considered as being less harmful than the other wavelengths.

“However, although hand hygiene has long been regarded as an important element of infection control activity, the author would not recommend these flashlights for checking the quality of hand rubbing. Although a YouTube video, some literature and a couple of photos have been uploaded on the internet about hand hygiene assessment using UVA, if used irresponsibly this radiation can cause tissue damage, especially on repeated use.”

What do you make of this research? Could it offer a practical solution to improve levels of hygiene in public places?