February 22, 2021
With the roll out of vaccines, the end of the pandemic seems in sight. Yet, UV-C disinfection is here to stay. Here’s why.
The germicidal effects of Ultraviolet light were first discovered in 1877, when sunlight was found to inhibit the development of pathogenic bacteria in test tubes left outside. A few years later it was discovered that UV-C light at a wavelength of 250 nm was a highly effective form of disinfection. Today, UV-C light is being used to help prevent the spread of the virus causing COVID-19. Other viruses and bacteria in the air, on surfaces and in water are also susceptible to its power.
As early as the 1930s and 1940s, William F. Wells, a Harvard University sanitary engineer, demonstrated the practicality of UV-C light to inactivate airborne viruses. Wells installed air disinfection luminaires in the classrooms of suburban schools in Philadelphia to see if they could prevent the spread of measles. Luminaires located on the back wall of a classroom, disinfected air passing over them which was then recirculated in the room through natural convection. Schools using the new-fangled luminaires saw a 13.3 percent infection rate compared to 53.6 percent for those that did not.1