COVID in Wales: How UV-C can disinfect the air we breathe

Viruses spread primarily through three vectors:

1. Direct airborne transmission between people – such as a cough or sneeze
2. Indirect airborne transmission through air flows – such as circulated air in a building
3. Indirect surface-borne transmission via contaminated surfaces – picking up an infected phone or piece of cutlery, for example:

One technology attracting interest is ultraviolet C (UV-C) lamps and luminaires.  UV-C as a technology isn't new – it's been used in hospitals and agriculture for decades to disinfect equipment, food and produce. The power of UV-C lighting for disinfection is well known with applications widely tested since the 1930s and 1940s. UV-C has been used for disinfection purposes across air, surfaces, objects, and water.  With the COVID-19 pandemic, there has been an acceleration of interest in this relatively under-sung technology. The technology has proven highly effective against all pathogens tested to date, including SARS-CoV-2, the virus causing COVID-19.

At a wavelength of 254 nanometres, the UV-C light inactivates viruses and bacteria by breaking down their DNA and RNA, rendering them harmless. For example, recent research conducted by Boston University shows that more than 99% of the virus that causes Covid-19 (SARS-CoV-2) was inactivated after just six seconds of exposure to UV-C light sources.

For more than 35 years, Signify (the former Philips Lighting) has been at the forefront of UV technology and has a proven track record of innovation and strong application expertise in UV-C lighting. Recently, new families of UV-C products have been launched – from fixed and mobile units that disinfect the air in a room, to chambers that disinfect objects, to ceiling and wall mounted luminaires that disinfect when no one is present.

Very recently, the University of Leeds announced that a study has been launched into the feasibility of using air cleaners to reduce the spread of COVID-19 in 30 primary schools in Bradford. As part of the pilot, ten out of the 30 schools are trialling Ultraviolet (UV-C) technology. This is an air disinfection approach that focuses on ventilation and involves cycling the air through an enclosed unit where it is exposed to an ultraviolet germicidal light, which inactivates microorganisms. Poor air quality is a major cause of illness, and children are particularly vulnerable to its effects. Many students fell ill due to the virus throughout the pandemic, posing a severe risk to their family's health. The UV-C devices installed are intended to provide an extra layer of protection for the students, staff, and visitors in the schools, providing the highest quality air, helping to reduce sickness and absenteeism. This pilot makes UV-C technology a perfect solution for trialling in Welsh schools.

In sports, PSV Eindhoven, RB Leipzig as well as Harlequins Rugby Club here in the UK are some recent examples of sports stadiums that have installed UV-C technology for the safety of their players. Every year we hear about teams affected by flu, resulting in them fielding weaker teams or playing havoc with fixtures. While COVID-19 was the primary driver for these clubs to install UV-C systems in their dressing rooms, it can help protect players all year round from airborne diseases such as seasonal flu creating a safer working environment for players and coaching staff.