Can light stop the coronavirus David Brenner

so let’s talk for a few minutes about

ultraviolet light so ultraviolet light

or UV light is a type of light that’s

actually pretty similar to the visible

light but it actually has different

wavelengths and that makes it invisible

to our human eyes and it’s been known

for more than a hundred years in fact

that some wavelengths of UV light are

incredibly efficient at killing viruses

and bacteria also so actually germicidal

UV light is pretty commonly used these

days to disinfect locations like

hospital operating rooms with the

problem we’ve always had this of if

people are deaf directly exposed to this

conventional germicidal UV light there

are potential hazards to our eyes and to

our skin and that really greatly limits

how and when we can we can use it so

what would what we’d really love is a

type of UV light which both kills

viruses but is also safe and about seven

or eight years ago we realized actually

there was such a type of UV light and

that’s why UVC light which has an even

shorter wavelength around 220 nanometers

so what we know is that fire UVC light

efficiently kills viruses and bacteria

too but all the available evidence and

here’s the thing is that it’s safe for

human exposure so if that’s that’s true

if FR UVC light really is safe and it

really does kill corona viruses then we

have a window of opportunity overhead

indoor fire UVC lights could be used to

kill viruses in indoor spaces where

people are present and so reduce the

risk of person-to-person transmission of

copied 90 and as we start to reopen

after the copied nineteen crisis slowly

widens down we hope

they’re going to be so many situations

where people are moving closer together

and indoor spaces hospitals of course

and nursing homes buses planes trains

train stations schools restaurants

offices shops theaters gyms the list can

go on forever in fact so the two

questions we need to think about first

of all is 5ec light safe and does it

really kill coronaviruses so what why is

it safe

well it’s safe because far UVC light

really can’t penetrate into any living

cells in our body a comp any trait into

our skin calm penetrate into our eyes

and that’s that’s purely physics and

let’s I’m a physicist by training so

it’s nice to see something that’s that’s

really physics based but that’s so

that’s that’s the conceptual reason but

over the past five or six years we we

and many other groups around the world

have done a lot of studies to season

really safe Studies on human skin on

Mouse skin on Mouse eyes in many

different situations and many different

countries and all seems to point to -

yes it really is safe but more than that

actually less this there’s a regulatory

framework in existence right now and

there are limits as to how much UV light

at any given wavelength so we can be

exposed to so the key of course is to

stay within those regulatory limits and

then the other part of the story is well

it doesn’t really kill coronaviruses and

the answer is for sure it does as you

know there are many human coronaviruses

and most steadily working our way

through through them and checking does

it kill this corona virus to kill this

corona virus moving up to the the Sask

Coby - virus and what we can say today

is that yes it’s very efficient at

killing corona viruses so if I UVC life

is really safe and it really can kill or

coronaviruses

in occupied indoor spaces and I think it

really does have the potential to be a

powerful tool in our battle against

carbon 19 and I might add not just that

against influenza and against the next

pandemic virus is different when it

comes and the sense is a little bit

different from a vaccine which is very

specific to one particular strain of

virus and so it sounds pretty positive

but that that’s not to say we should

stop using the weapons we already have

we certainly shouldn’t stop using masks

we certainly shouldn’t stop prattling

social practicing social distancing but

we do I think now have a new and

potentially powerful weapon in our fight

against this terrible violence

[Music]

tastic thank you so much for that it

does sound like it could be a real real

game-changer if I can use that cliche it

has that potential yeah so walk us

through exactly how this far UVC light

can kill a virus but not harm you know

human skin cells or eye cells or

whatever else well the reason is

basically it’s a physics reason as I was

saying that far UVC light really can’t

travel very far in any sort of

biological material so right on the

surface our skin for example is a layer

of dead cells and the this far UVC light

simply can’t penetrate through those

dead cells and and so reach the living

cells in the skin in the in the

epidermis and the dermis and the same

goes for the eye on the very surface of

our eye that’s that’s some liquid called

the tear layer and 5ec light can’t

penetrate that either so it can’t reach

the the living cells in the iron in the

cornea or deeper down in the lens for

example so that’s there’s a really good

physics reason why the far UVC light

can’t penetrate into living cells in our

bodies that said bacteria and viruses

are very much smaller entities and so

the far UV light really does have enough

range to penetrate them and then kill

them so that’s why it can kill viruses

but in principle is safe for for human

exposure so it’s a kind of defense and

depth because we have multiple cells

kind of layered down were more defended

against this particular wavelength than

a virus or a bacteria would be that’s

right and right on a surface of our skin

and our eyes a non-living cell so

doesn’t matter if the fire UV sees is

absorbed there as long as it doesn’t

reach the the living cells in our skin

or in our eyes now the next question

which i think is true for all travel at

light is that in our atmosphere any way

it creates ozone

and that’s a little bit of a human

health hazard have you looked into that

side of things at all if there is kind

of ozone creation when you when you have

these lights on yeah for sure

but in fact this this fire UVC light is

not really at the wavelength that

produces very much ozone so we always

measure and monitor the amount of ozone

that’s been produced and it’s absolute

miniscule it’s it’s way way below the

EPA levels for ozone safeties so I don’t

think that’s gonna be an issue so

fantastic save for our skin and say for

our eyes safe for our lungs that’s

that’s a that’s a pretty good trio let’s

see what the audience is curious about

we’ll take that first question please

how may far UVC light be used in

settings limited by an easily accessible

stable source of electricity so this is

the power question yeah that’s a good

question but then the bottom line is any

such of indoor situation where you have

regular visible lighting and you have

powerful for that the fire UVC light is

going to be applicable there it doesn’t

you have any special particular needs in

terms of electricity so as long as you

in your indoor setting you have enough

electricity to power regular lights you

can use you’ll be able to use fire UVC

lights and sometimes and some of the

manufacturers are building in the the

fire UVC light and the visible light

engine to warm fixture some

manufacturers are having said Rip’s

fixtures for the fire UVC light and the

visible light but either way they’re

really not any particular electrical

limitations so wait a minute actually

visible light light bulbs that that also

incorporate the the far use far UVC

wavelength to have a sterilizing effect

yeah not in 1:1 bulb but the idea of on

some manufacturers is to have a fitting

a fixture I should say which

both a visible light in it and a fire

UVC light maybe one surrounds the other

one so but it’s a single fixture and

other manufacturers are thinking of well

we’ll have to separate fixtures one one

for the visible lights that we already

have and one for the fire UVC lights but

always what we’re thinking about putting

these far UVC lights essentially in the

ceiling in the same location is where

we’d have the visible light so as long

as the visible light can light up the

room the far UVC light will be able to

expose the room in the same way is there

any limitation on on distance or you

know however far the light can spread

the the sterilization effect will will

occur well in just in the same way as

when you when you have a room you have

to figure out well what sort of visible

lighting am I going to have in this room

if it’s a big room you’re gonna have to

have several lights and it’s small room

may only have one light and that’s the

same thing for fire UVC light if we’re

talking about a big room and lighting in

an airport for example just a very large

room you’re gonna have to have a few

fire UVC lights overhead in the ceiling

and if it’s a small room and an elevator

for example you definitely only have to

have one light so the same story is it’s

a regular visible light got it

let’s have that next audience question

please can UVC far UVC kill viruses fast

enough to neutralize the virus particles

born on aerosols in the air yeah that’s

a that’s a really good question it’s a

pretty central question and we look upon

it this way so if you and I David and I

are in a room together and maybe with

other people and we’re coughing and

sneezing some of us so over the over

time in that room that the level of of

aerosols and viruses in the air is going

to start to build up so what we really

need is something that will continuously

keep that level of virus down so we

would like 99.99% killing in a few

minutes and that we can achieve but the

bottom line is to keep the level of

virus in the air as low as possible as

the lower the level of virus in the air

the less chance there is that it can be

transmitted from one person to another

so it really is just keeping the level

of virus long term in the in the air in

that room as low as possible so that

implies that these lights would kind of

be always on so that they’re always

having that sterilization effect is that

is that indeed you’re you’re thinking

that these these far UVC lights would

kind of always be on even though we

can’t see them well they could be they

could be always on or there could be on

a significant fraction of the time and I

don’t think it would be very useful to

have the lamps on at eight o’clock in

the morning for five minutes and then

turned it off the rest of the day

because the whole point is to keep

killing the viruses as they’re being

produced whereas people sneeze and cough

and talk and shout so we don’t

necessarily have to have it on every

moment of the day but we don’t want to

have it on just once a day and that that

that’s not the concept do you think so

the does the Sun it must put out

wavelengths or it must put out light at

this wavelength is that a pasa is there

a possibility that the that the Sun is

providing some of the sterilization in

an outdoor setting yeah well no actually

it doesn’t

so though there are three types of UV

light as UVA and UVB and UVC and but

just different they’re different

wavelengths UVC is the one that kills

viruses bacteria most efficiently the

Sun produces UVA and UVB and UVC so they

wing their way towards the earth but

when they get to the atmosphere the UVC

is entirely absorbed in the upper

atmosphere I see in the ozone layer in

the atmosphere so down here on the

ground

we don’t feel any UV

see at all the only feel UVA which is

where we get some Sun tans from and UVB

and those are not very efficient at

killing viruses bacteria it’s really UVC

which is the one which is very efficient

at killing viruses and that doesn’t

naturally occur here on the ground

gotcha so we only get the the Sun

burning in my case UV we don’t get that

we don’t get the good yeah there’s no

doubt that UVA and UVB kill a little bit

of bacteria and viruses but not much and

anyway we believe the whole story really

is indoors I mean that’s where most of

the transmission from from put from one

person to another occurs there may be

some outdoors but it’s it’s pretty

limited compared to indoors I think

we’re all concerned mainly about being

in close proximity to one another in

indoors that’s right I mean I think my

top concern as a New Yorker is is the

subway which is very indoors they are

using UV light but it’s this UVA or UVB

light right and they can only use it

when humans aren’t present so in the New

York MTA system they are using

conventional germicidal UV light which

is UVC but as I said in my introductory

words that has the potential for for

health issues it’s directly exposed on

people so what what the what the MTA are

doing is at the moment the MTA is closed

down between I think it’s 1:00 a.m. and

5:00 a.m. something in the wee hours so

they’re moving the conventional

germicidal UV lights into the into the

buses and into the trains and

essentially sterilizing the trains and

buses overnight which is a good thing

but come 5:00 a.m. in the morning you

have a nice clean subway car but come

5:30 in the morning when people start

walking into the

that subway car it’s over the course of

the day is going to come become more and

more contaminated so while it’s a good

thing because you’re starting from a

from a clean train by the end of the day

the the effects are probably more or

less gone away so what we really want is

something that can be used continuously

or more or less continuously during the

day when people are around

so to kill the bugs as they’re being

produced by by people sounds good to me

let’s take that next audience question

please is it practical to use the far

UVC products that are on the market

today

so the ones that are already out there

for our home or office environments or

anywhere else well I must say that we I

mean we haven’t really addressed the

issue of are these fie UVC products

really available and the answer is

somewhat so there are several

manufacturers and more starting up

pretty well day by day but they really

started ramping up production only as

The Cove in nineteen crisis hit us which

is not that many months ago if you could

believe that so that their their

capacity right now is relatively limited

so it’s it would be fairly hard for

someone who wants to install one of

these things in their home to get all of

these lands I guess it’s possible but

they are really ramping up production

pretty rapidly and so towards the end of

the year I think there will be really a

lot of these far you see products around

so is this being and that would imply

that maybe people are are starting to

implement this somewhere in the world is

that is that the case yeah there are

certainly test projects going on in a

variety of different locations and so

some here in New York City I will say

and

that’s pretty exciting I would think

that that may be your home institution

Columbia University could find a good

finding use for them and that’s indeed

correct and Columbia University’s is

indeed looking very strongly at these

things we hope to have those in place in

the not-too-distant future and then that

will give us more safety information I

imagine so let’s take that next audience

question please could a UVC light be

added to a mask device that wouldn’t

need to filter them just kind of kill

the virus I’m imagining this sort of

like a headlamp wrong yeah not so sure

that that would be practical you need a

power supply for example for the UV

light so be a pretty bulky device and

really we see this mostly it’s not not a

personal protective device but for us as

a social product protective device so a

roomful of people that’s where we’d like

to have the lights in place so that

we’re just keeping the level of virus

down as much as possible in that room

rather than this as a PPE type device

that brings to mind if we put these

everywhere we’ll viruses or bacteria

begin to evolve to resist far UVC I mean

they’d seem pretty canny at doing that

relatively quickly yeah well we don’t

think so because I mean as I said UBC

likes being has been used for some

decades now to sterilize different

different situations different rooms and

there’s no evidence for any and UV

resistant viruses in emerging and

there’s a good reason for that it’s a

little bit different from a drug

resistant bacteria

emerging from when

user drug because the drugs very much

focus on one particular aspect of the

virus in order to kill it UV is more

like hitting the virus with us the RNA

in the virus with a sledgehammer so you

can’t predict exactly where it’s going

to produce the damage within the RNA so

it will be very very hard for a virus to

evolve which is able to somehow repair

RNA damage anywhere within its genome

it’s a little different from a drug so

we certainly don’t expect that and

there’s no evidence that a candy virus

has appeared in in terms of UV

sensitivity so an invisible blaster just

blown apart viral particles and bacteria

wherever wherever it may find them

sounds very science fiction to me well I

hope it’s physics actually coming into

into real life and I think that’s guess

what science fiction is but it does seem

practical and I don’t think it will

necessarily be invisible UV like you’re

absolutely right is invisible but most

of the manufacturers that I see are

using the fact that the lamps actually

produce a little bit of purple light at

the same time now that purple light is

not in any way killing killing the

viruses but I think it’s showing people

around that the lamp is on and giving

people some sort of reassurance that

they are being protected by the UV light

so I think most of the manufacturers are

thinking we’ll keep that low level of

purple light in in these lamps so

they’re not there will be completely

invisible that makes sense it’s in kind

of the social engineering is as

important as the physics engineering

right yes for sure if people don’t don’t

accept the use of these things it won’t

be very useful but we’re all looking for

different ways to to protect ourselves

in public spaces and as we come closer

and closer together so certainly talking

to people there’s

a remarkable degree of excitement about

the potential for fly UVC light so take

us take us back in your own personal

journey with far UVC light when did you

first realize that you know this had

this potential to to combat all these

these troubling pathogens well we we

were originally thinking not about

viruses but about bacteria which offers

both both nasty pathogens and my

original motivation was that I had a

friend who passed away from a drug and

drug resistant bacterial disease and I

was thinking long ago anything physics

can Cantera surtout to try and stop this

problem so we thought very much in terms

of reducing surgical site infections in

hospitals by killing drug-resistant

bacteria but again with the same idea

that it’s going to be safe for human

exposure so the first few years we

thought about it and we worked on really

entirely on bacteria and then two or

three years after that the penny dropped

that actually we could use this for

viruses - viruses are also very very

small like bacteria and there was no

copy 19 at that point so we were

particularly thinking about influenza we

should never forget that influenza is a

as a very very nasty virus which kills a

lot of people every year um no doubt

we’ll continue to do so so what we were

looking at 5ec light war was to

essentially try and limit the seasonal

influenza epidemic that we have every

year and which kills an awful lot of

people every year so we’ve been slowly

working the last three or four years

really in the influenza world

so then can there be any of this year in

kovin nineteen appears they

it became immediately apparent to us

that the ideas that we’d have for

influenza were going to be applicable to

cough in nineteen because again it’s

transmitted from person to person

primarily in influenza case by airborne

routes so all the concepts that were

that were developed for influenza seem

to be applicable to the coab in nineteen

prices so the first thing we started to

do was do some measurements can the fire

UVC light kill corona viruses in the air

and the answer which we actually just

published or recently is yes we

certainly expected that it would kill

corona viruses and and it does great

news and I think we should get these

into hospitals stat that seems like the

first a great application and has many

co benefits but I know we’re running out

of time so let’s try to get in one more

audience question before we have to wrap

up so from Stephan patron ik we live in

a symbiotic relationship with bacteria

many of which are essential to life

would this create such a sterile

environment that it would ultimately be

harmful to us yeah well that’s a really

good question because it’s undoubtedly

that there are bad bacteria which was

just talking about like Mrs T but there

are good bugs too and they are essential

for us so most of the the microbiome

that that would help us or inside our

bodies are inside our gut for example

and that’s not going to be an issue

because I UVC light simply can’t reach

into into the gut it can’t penetrate

into the body as we talked about but

there are there is a skin microbiome

actually on them on the very surface of

our skin and that’s something we think

about a lot but if you think about it

how many times have you washed today

many so and that is going to be more

damaging to the skin microbiome then 5ec

life will be um so what we know of the

skin microbiome by definition it’s it’s

really

I can resist a lot and even when it’s

removed it comes back pretty quickly so

we don’t think that we skin microbiome

is going to be a significant issue

certainly it’s just as long as we keep

washing there’s going to be more damage

to the skin microbiome than there’s

going to be from five ABC night and

that’s why we keep washing our hands

even it once these far UVC lights become

available so I think we have time for

one final audience question let’s let’s

see if we can sneak it in from Terry

Moore what problems need to be solved to

make this technology happen now how can

the Ted community help well that’s a

very good question from from a from a

ted friend and i think the the biggest

problem needs to be solved now and we’ve

alluded to it in our conversation is

building up the capacity for these lands

industry really only started building

these lamps in the spring so the

capacity really isn’t there for the

millions of lamps that there is a demand

for right now so there are a few aspects

of that one is well it would be really

nice if there was a simpler cheaper

technology producing these lamps the

lamps are not particularly expensive and

they’re not particularly complicated but

if it could be made much cheaper and

much simpler to manufacture and i’m

thinking perhaps particularly about the

LED just in the same way as leds slowly

are replacing conventional light bulbs

LEDs potential have a potato for for

replacing the current ice type of i UVC

light would be quicker would be easier

to make probably cheaper

probably longer lived so the science

community I think could certainly be put

a little more attention but I’m

certainly thinking about it two

different technologies to make the far

UVC production capacity happen faster

and happen cheaper so yeah that’s that’s

a little call to the optics community

around us let’s let’s develop some LED

lights at these far UVC wavelengths

fantastic well thank you David

for joining us and sharing this ray of

hope in these pandemic times thank you

so much there’s been a real pleasure

thank you