04/29/2020
From The Washington Post
“Light kills viruses”
Brenner and his team at Columbia have begun testing their special 3-by-3-inch lights against the novel coronavirus, which has killed more than 210,000 people worldwide.
One colleague, physicist David Welch, is calibrating exposure from the lamps. Another, Manuela Buonanno, is testing how many viruses survive.
They killed two batches of less-threatening coronaviruses in recent weeks with a very low level of exposure, according to research released Monday, and Brenner said things are looking good so far with the one that causes covid-19.
Brenner believes the technology could address the problem of a virus-spewing airplane passenger.
“You’re sitting there and the guy right behind you sneezes. . . . All the filters in the world aren’t going to help you,” Brenner said. “I think the lamp would potentially deal with that.”
What takes longer is conclusively proving the long-term safety for people exposed to the light, a type of radiation known technically as far-UVC light. Traditional ultraviolet lights are used to clean water supplies and sanitize operating rooms, but only when no people are under them, because they can cause cancer and eye damage.
But Brenner said far-UVC light is different. It is generated at the far end of the ultraviolet spectrum and is “not in any way penetrating.” It barrels right through air or droplets containing viruses, but is quickly absorbed — and stopped — by the protein in dead skin cells or in the layer of tears on the surface of the eyes, Brenner said.
“In order to produce any damage, it has to get to the live cells,” he said. “Not once have we yet seen any hazardous effects.”
Could the light somehow sneak through and cause damage?
“I think the answer’s no. That’s why we have all those mice sitting upstairs in this long-term study,” Brenner said.
Brenner has studied the effects of CT scans, nuclear plants and dirty bombs. He and his colleagues developed a commonly used radiation protocol for fighting prostate cancer. He initially thought of the lamps as a weapon against infections during surgeries, after a good friend died of one.
There are challenges, including the need for a huge supply of the lightbulbs, though he said industry is already ramping up for that. The lights are mainly for targeting viruses in the air, since they might hide in the tiny shadows of upholstery, he said. A closed tray table would also be a problem.
Boeing said its lavatory prototype uses far-UVC lights, which are “not harmful to humans.” The company said it could not speak directly to the Columbia research but is pursuing creative “cabin upgrades.”
Airbus declined to say if it would consider the lights, and the FAA would not say if it supports the idea.
The Columbia researchers have been palpating the skin of the mice and looking for lesions on their corneas. Some of the males are getting a bit antsy from being cooped up, but otherwise are looking good, Brenner said. At the end of the study, researchers will check them for any subtle DNA damage.
As scientists scurry to develop vaccines, viruses traverse the globe along with people, moving “from city to city. They go by train or plane or buses,” Brenner said. “If you can target transportation modes in some way, you could do a lot of good.”
