It is not difficult to remove airborne microbes wherever people gather — in public libraries, waiting rooms, cafeterias, or restrooms where someone coughed hard moments earlier. Exhausting air outside is effective but can sometimes be difficult. The any-season, inexpensive, lasting solution is GUV.
Placed near the ceiling, GUV nearly annihilates microbe infectivity. GUV is a proven potent disinfectant for coronavirus, either in
fluid or airborne, and has been used to disinfect surfaces for decades. 16 seconds of ultraviolet-c radiation (UV-C) exposure
inactivated 82% of an aerosolized dose. GUV efficacy against highly-resistant TB, which is primarily transmitted through the air, was
proven in a multinational-CDC-WHO study. In our Philadelphia TB Clinic in 1993, we also installed inexpensive ceiling fans, run at low speed, switched to pull the air up instead of down, to help assure air mixing and fastest microbe inactivation, an approach
endorsed in the 2015 multinational report.
Attention to
safety and detail in upper-room GUV installation is required to protect skin and eyes from potential overexposure. High doses of UV-C can cause cancer and cataracts, but accidents are avoidable. Additionally,
tests are underway with a shorter wavelength form of UV-C that has so far proven to be harmless to human skin cells while still destroying airborne microbes, making it potentially viable for use in occupied public spaces.
We should prioritize installing GUV now in spaces like ERs, ICUs, dialysis centers and clinics, congregate settings like prisons, followed by any other public and private spaces where the public gathers. Retrofitting is inexpensive. Five-star hotels can buy GUV tricked out like a Cadillac, but GUV is also produced as inexpensive UV-C fluorescent tube fixtures screwed high on the wall in simple ballast fixtures. Bulbs last 9000 hours. Repainting the ceiling with dark non-reflective paint, protective strips or
egg-crate ceilings reduce UV-C light reflected below. The total
output needed is just 1⁄2 milliwatt per cubic foot. A bar-restaurant or waiting room sized 40’ x 50’ with 8-foot ceilings (16,000 square feet) needs just two 20-inch 15-watt 254 nm fluorescent tube fixtures ($175 each) with a total GUV output of just 8 watts (efficiency about 28%).