Dr Jim Malley of the International Ultraviolet Association tells HEQ about the potential of UV technology in infection control.
In 2020, the issue of infection prevention and control – particularly in hospitals and clinical settings – has been understandably at the forefront of healthcare discourse. One technology which has received substantial attention is ultraviolet (UV) disinfection, whereby UV radiation is applied to spaces and surfaces to prevent the spread of disease.
Based in Maryland, US, the International Ultraviolet Association (IUVA) was established in 1999 with the aim of providing a platform for companies and bodies involved in the research, development and production of UV-based technologies. Dr Jim Malley, Professor of Civil and Environmental Engineering at the University of New Hampshire and Editor-in-Chief of the IUVA’s UV Solutions publication, speaks to HEQ about the potential of UV disinfection as a tool for infection control.
How does UV disinfection work? What are the key benefits of disinfecting air and surfaces with UV light, as opposed to chemical cleaning methods?
We often refer to UV disinfection as a physical disinfectant, as opposed to chemical disinfection methods: UV light of a certain wavelength can damage the nucleic acids, DNA or RNA, of an organism which normally might give us an infection – this could be bacteria, viruses or fungi. The damage which UV radiation causes to an organism’s DNA or RNA makes it impossible for the pathogen to reproduce; this means that it therefore cannot infect the human host. There has been some research recently into the effects of UV light on viruses specifically, which appears to indicate that in addition to altering the nucleic acids of a virus, UV can also damage the proteins which code the virus and enable it to attach itself to a human cell. In essence, UV radiation causes damage to some vital part of the disease-causing organism.
If we can deliver UV disinfection correctly and safely we wind up with a very rapid method of disinfection: UV literally disinfects at the speed of light. Disinfection with UV is free of any chemical residue; it’s an entirely dry process, so there are no liquids to worry about as there are with most chemicals. The other significant benefit is that it is often quite straightforward to take UV – which is essentially an electronic technology – and put it into a device for optimum delivery. Robots, for example, can be moved through an area very efficiently and effectively while emitting UV radiation to disinfect nearby surfaces.
Which potential applications of UV disinfection could help prevent the spread of COVID-19?
What we’re seeing quite a bit around the world right now is basically much more widespread adoption of the UV technology that was developed within the healthcare industry – over the last 10 or 15 years, concern over healthcare-acquired infections (HAIs) has led to the use of a lot of UV robots in hospital suites, surgical theatres and other clinical settings.
Those UV robots, which are already being used around the world, vary widely in complexity: there are very simple ones which are propelled by human users and the modern extremely high-tech ones equipped with Artificial Intelligence (AI); and they are all really becoming popular, whether for use in a classroom, a hospital suite, subway car, a bus or any other public space. UV drones are a new, interesting angle: people are beginning to consider the use of a UV drone in settings like cruise ships or some sort of large area where they could be efficiently piloted.
The IUVA has issued a warning reminding people that UV light should not be directly applied to the body in an antiviral context. Has misinformation become a greater issue for the UV industry during the COVID-19 pandemic?
Since around mid-March there has been a noticeable rise, not only in the public’s interest in ultraviolet technology and sales of ultraviolet devices, but also in the misinformation – particularly in terms of stretching the limits of UV safety. There have been a number of articles making a number of claims that certain types of ultraviolet disinfection wavelengths can be applied directly to the human body or people can walk through a UV portal as an effective disinfection technique.
The IUVA, along with the World Health Organization (WHO) and a number of others, are trying to remain conservative and emphasise that with UV radiation of any wavelength, we need to protect our eyes and our skin from exposure.
How can companies and hospitals hoping to invest in UV disinfection technology ensure that they are purchasing a safe, reliable, effective product? What are some warning signs that a product may not have the effects it claims?
There are a number of red flags to watch out for. Unfortunately, here in the United States and around the world there is no real validation protocol for UV devices in the same way that there are for objects like cell phones, car keys, or even for air. We are hoping that someday there will be a validation protocol – maybe a certification or a seal of approval of some kind. The only place we see that right now is when ultraviolet technology is used in the processing of water: for drinking water, wastewater, and water reuse.
In these UV ‘disinfection’ products which are sold to the consumer for their cell phone or their living room, what we have been finding in our research laboratory is that as many as 50% or 80% of them are not very effective. The consumer can look at a few basic things: normally, you are going to get what you pay for; so if a product is very inexpensive, it probably doesn’t work very well. Sometimes logic can be a factor in selecting a product. One thing that is absolutely true about ultraviolet is that it is what we call a ‘line of sight’ technology. This means that the UV radiation has to be able to reach the surface or area where we want it to perform the disinfection; and what we find with a lot of these devices which are on the market is that once you place your objects in the UV box or device to be disinfected, they will actually block the UV light – and so in a lot of cases, the objects which are purportedly being disinfected are not receiving disinfection on all their surfaces.
Sometimes it may help the consumer to ask: who has been using this effectively? Do we find it in use in home health? Are we finding it in hospitals? This can be a good indicator.
Can you tell me about any significant recent developments or innovations in UV technology?
The research currently coming out into far-UV disinfection technology is very exciting; it’s peer reviewed, which we always look to as a good indication of quality. So far the results of trials on laboratory animals and different theoretical models have indicated that far-UV works very well and may not be as damaging as conventional UVC radiation to human skin or human eyes. However, to date all this research is in the form of animal testing and hypotheses; and so the IUVA, along with a number of other industry groups, is saying: this is very promising, it’s exciting research, but until there are clinical trials with human volunteers we still cannot advocate for direct use of UV.
We are also seeing a substantial increase in the capacity to monitor and analyse the effectiveness of UV: there are now a number of small, low cost sensors available, which can give us an idea of the dosage of ultraviolet which is being produced. UV light-emitting diodes (LEDs) have been a source of some interest and excitement for five or 10 years; and they are continuing to be very promising: they allow us to do a lot of things with ultraviolet that the older traditional lamps wouldn’t allow us to do. As they are small and can have a very interesting geometry, they don’t have to take the form of a traditional lamp or a fluorescent tube; they are mercury-free, which is very exciting from an environmental perspective; and we can use them to form almost any shape: in the automotive industry, for example, we could one day have a UV LED taking the shape of a door handle or a railing in a subway station, for instant disinfection of high-touch surfaces. Right now they are still best suited for larger applications: they are not quite cost competitive yet and have a low power ceiling, but they are very attractive as a potential solution for the future.
Consumers and the public need to bear in mind that UV is just one tool in the toolbox. It’s one of several barriers to infection. We don’t want people getting a false sense of security and thinking because we are using UV disinfection that we don’t also need to observe social distancing, wash our hands or wear masks. That’s not true. It’s just another tool; it’s not magic; it’s not a silver bullet; we do still have to take those additional precautions to protect ourselves from COVID-19.
Dr James Malley
Editor-in-Chief, UV Solutions
International Ultraviolet Association