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