Transcript: How COVID-19 Is Airborne | Jan 11, 2022

Steve Paikin sits in his home office, which has the Ontario flag and a framed photograph of Walter Kronkite hanging on white walls behind him.
Steve wears a light blue dress shirt and a blue checkered tie. He is clean-shaven and has short brown hair.

Text reads, How Covid-19 is Airborne.
@spaikin @theagenda

Steve says, LAST MONTH, THE
CO-CHAIR OF ONTARIO'S COVID-19
SCIENCE ADVISORY TABLE, STEINI
BROWN, PUT IT BLUNTLY WHEN HE
SAID THAT "COVID IS AN AIRBORNE
DISEASE -- I THINK THAT'S
CLEAR."
BUT THAT HASN'T ALWAYS BEEN
CLEAR, SO HERE TO HELP EXPLAIN,
IN THE NATION'S CAPITAL:
WE'RE JOINED BY
DR. SARAH ADDLEMAN, OTTAWA-BASED
PHYSICIAN AND ASSISTANT
PROFESSOR OF EMERGENCY MEDICINE
AT THE UNIVERSITY OF OTTAWA.
DR. ADDLEMAN, IT'S GOOD TO HAVE
YOU ON OUR PROGRAM.
HOW ARE YOU DOING TONIGHT?

Dr. Addleman sits in front of a white bookcase full of books. Several small plants sit atop the bookcase. She has curly shoulder-length brown hair and wears a dark blue open-necked blouse.

Dr. Addleman says,
I'M
GOOD, THANK YOU.

Steve says, GREAT TO HAVE YOU
HERE.
IN TERMS OF THE KEY WAYS THAT
THIS VIRUS IS TRANSMITTED, HOW
IS AN AEROSOL DIFFERENT FROM A
DROPLET?
BECAUSE WE'VE HEARD A LOT MORE
ABOUT THE LATTER THAN THE
FORMER.

Text reads, Aerosol vs. Droplet.
Sarah Addleman. Emergency Room Physician.

Dr. Addleman says,
RIGHT.
SO, AN AEROSOL IS A VERY LIGHT
PARTICLE THAT REMAINS SUSPENDED
IN THE AIR.
AND THE TIME OF SUSPENSION AND
THE DURATION OF TRAVEL IN THE
AIR REALLY DEPENDS ON FACTORS
SUCH AS AIRFLOW AND VENTILATION.
SO, THIS IS OPPOSED TO A DROPLET,
WHICH IS A MUCH HEAVIER PARTICLE
WHICH IS EMITTED FROM THE
RESPIRATORY TRACT AND WHICH WILL
FALL TO THE GROUND CLOSE TO THE
SOURCE AND IT FOLLOWS A MORE
BALLISTIC PATHWAY, IF YOU WILL.
SO TO INFECT SOMEONE, IT HAS TO
LAND IN THEIR MOUTH, NOSE, OR
EYES.
AND AS I MENTIONED, IT'S NOT
GOING TO STAY SUSPENDED IN THE
AIR FOR VERY LONG.
WHEN WE THINK ABOUT OUR 2-METRE
RULE, THIS IS BASED ON DROPLET
TRANSMISSION AND A DROPLET
FALLING CLOSE TO THE SOURCE.

Steve says, WE'VE HEARD THERESA
TAM USING OMICRON TRAVELLING
THROUGH THE AIR AS SOMETHING
SIMILAR TO SECONDHAND SMOKE.
IS THAT A GOOD ANALOGY TO USE?

Text reads, Butt Out.
Sarah Addleman. University of Ottawa.

Dr. Addleman says,
I LOVE THAT ANALOGY.
I WOULD SAY AEROSOLS ARE LIKE
SECONDHAND SMOKE.
I THINK THIS IS EASY FOR US TO
CONCEPTUALIZE AND DR. TAM DID IN
FACT USE THIS ANALOGY A COUPLE
OF MONTHS AGO, ALTHOUGH IT WAS
FIRST DEVELOPED BY THE AEROSOL
SCIENTIST DR. LINDSAY MAR.
IF YOU THINK ABOUT AEROSOLS AS A
PLUME OF SMOKE EMITTED BY A
PERSON, YOU CAN IMAGINE HOW THEY
CAN LINGER IN THE AIR, YOU CAN
IMAGINE SORT OF SEEING THE SMOKE
TRAVEL, THAT THAT TRAVELLING IS
GOING TO DEPEND UPON FACTORS
SUCH AS AIR FLOW.
YOU CAN ALSO IMAGINE THEN THAT
IN A POORLY VENTILATED SPACE,
THE AEROSOLS ARE GOING TO STAY
LINGERING IN THE AIR MUCH
LONGER, SO AGAIN SIMILAR TO
SMOKE.
AND THAT REALLY DRIVES HOME THE
IMPORTANCE OF VENTILATION.
YOU CAN IMAGINE THAT WE OPEN A
WINDOW AND DILUTE THE AIR,
YOU'RE GOING TO HAVE A DECREASE
IN THE AMOUNT OF SMOKE IN THE
AIR.

Steve says, LET ME PICK UP ON
VENTILATION.
IS IT ALSO POSSIBLE THEN THAT IF
YOU HAVE AEROSOL IN ONE ROOM, A
VENTILATION SYSTEM COULD TAKE IT
INTO ANOTHER ROOM AND YOU COULD
CATCH OMICRON THAT WAY?

Text reads, Going the Distance.
Sarah Addleman @S__Addleman

Dr. Addleman says,
SO, THIS IS POSSIBLE.
THIS IS UNLIKELY TO BE THE MOST
COMMON CAUSE OF TRANSMISSION.
AND I CAN BRIEFLY GO THROUGH THE
DIFFERENT MODES OF AEROSOL
TRANSMISSION.
SO, THE FIRST ONE AND THE MOST
COMMON IS GOING TO BE CLOSE
CONTACT TRANSMISSION -- I SHOULD
SAY TRANSMISSION AT CLOSE RANGE.
SO, IF I AM EMITTING AEROSOLS OR
AGAIN IF YOU THINK ABOUT
SMOKING, IT'S THE PEOPLE CLOSEST
TO ME THAT ARE MOST LIKELY TO BE
INFECTED, WHO ARE MOST LIKELY TO
INHALE THOSE INFECTIOUS
AEROSOLS.
THE SECOND TYPE OF TRANSMISSION
IS WHAT WE REFER TO AS SORT OF
SHARED ROOM AIR TRANSMISSION.
SO THIS IS ONE OF THE BASIS FOR
OUR SUPER SPREADER EVENTS.
AGAIN, IF YOU IMAGINE A BIGGER
ROOM WITH LOTS OF PEOPLE IN IT,
BUT SEVERAL PEOPLE MAY BE
SMOKING IN THAT ROOM AND THERE
MAY BE POOR VENTILATION AND
SOMEONE FAR AWAY AT THE OTHER
END OF THE ROOM MAY STILL END UP
INHALING THOSE AEROSOLS, OR THAT
SECONDHAND SMOKE.
IT'S STILL GOING TO BE MORE
CONCENTRATED CLOSER TO THE
SOURCE, SO THE PEOPLE CLOSE BY
ARE STILL MORE LIKELY TO BE
INFECTED BUT PEOPLE FAR AWAY CAN
GET INFECTED AS WELL, AND WE SAW
THAT WITH THE SUPER SPREADER
EVENTS SUCH AS THE CHOIR IN
WASHINGTON STATE, FOR EXAMPLE.
THE THIRD ONE WHICH YOU JUST
REFERRED TO IS THAT LONGER RANGE
TRANSMISSION WHEN SOMEONE IS NOT
EVEN IN THE ROOM.
THIS IS HARDER TO PROVE AND
CERTAINLY OCCURS MUCH LESS -- WE
THINK OCCURS MUCH LESS
FREQUENTLY.
BUT DEPENDING ON AIRFLOW, IT IS
POSSIBLE, AND, YOU KNOW, THIS IS
THE KIND OF THING THAT
TRADITIONALLY WE THOUGHT OF AS
MORE SYNONYMOUS WITH AIRBORNE
TRANSMISSION.
BUT WHAT WE'VE LEARNED OVER THE
LAST ALMOST TWO YEARS NOW IS
THAT AIRBORNE TRANSMISSION
REALLY ENCOMPASSES ALL THOSE
DIFFERENT TYPES OF
TRANSMISSIONS.

Steve says, AND I PRESUME THE
OMICRON VARIANT SPREADS MORE
EASILY THROUGH AEROSOL THAN ITS
PREDECESSOR VARIANTS; IS THAT
RIGHT?

Text reads, Observing Omicron.

Dr. Addleman says,
YOU
KNOW, I DON'T THINK WE KNOW FOR
SURE YET.
WE DO KNOW THAT IT'S MORE
CONTAGIOUS.
I MEAN, WE'RE SEEING IT
SPREADING LIKE WILDFIRE THROUGH
OUR COMMUNITIES.
WE THINK AT THIS POINT THAT
THAT'S CERTAINLY PARTLY BASED ON
ITS IMMUNE EVASIVENESS AND ALSO
IT'S LIKELY INHERENTLY JUST MORE
CONTAGIOUS.
WE DON'T KNOW IF IT TRANSMITS
MORE BY AEROSOLS THAN THE OTHER
VARIANTS.
WHAT WE DO KNOW IS THAT ALL OF
THE VARIANTS HAVE BEEN AIRBORNE.
IT JUST SEEMS TO BE MORE OBVIOUS
TO EVERYBODY WITH OMICRON.

Steve says, LET ME SHARE WITH
YOU AND OUR VIEWERS AND THOSE
LISTENING ON PODCAST AS WELL.
THIS WAS A TWEET FROM THE WORLD
HEALTH ORGANIZATION IN MARCH OF
2020, AND IT SAID: "FACT:
COVID-19 IS NOT AIRBORNE.
THE CORONAVIRUS IS MAINLY
TRANSMITTED THROUGH DROPLETS
GENERATED WHEN AN INFECTED
PERSON COUGHS, SNEEZES, OR
SPEAKS."
AND THEN IT GOES ON TO SAY WHAT
YOU SHOULD DO TO PROTECT
YOURSELF.
NOW, ADMITTEDLY THAT TWEET CAME
IN THE FIRST MONTH OF COVID-19
WHEN PRESUMABLY AUTHORITIES
DIDN'T KNOW AS MUCH AS THEY KNOW
TODAY, BUT IT DOES RAISE THE
QUESTION OF WHY IT MAY HAVE
TAKEN SO LONG TO ACCEPT THE
NOTION THAT COVID-19 WAS
AIRBORNE AS OPPOSED TO DROPLET.

Text reads, Slow to Accept.

Dr. Addleman says,
YES.
IT'S A VERY INTERESTING QUESTION
AND THERE ARE DEFINITELY A LOT
OF THEORIES ON THAT.
WHEN WE THINK BACK TO JULY 2020,
WE MIGHT RECALL THAT THERE WAS A
LETTER SIGNED BY OVER 200
AEROSOL SCIENTISTS REALLY
DIRECTED TO THE W.H.O. ASKING
THAT THEY PRESENT THE EVIDENCE
IN FAVOUR OF AIRBORNE
TRANSMISSION AND REALLY
REQUESTING THE W.H.O. REVISE ITS
GUIDELINES.
AND IT'S TAKEN A LONG TIME AND
WE HAVE SEEN A SHIFT NOW IN THE
LAST FEW MONTHS WITH THE
MAJORITY OF THE PUBLIC HEALTH,
THE ORGANIZATIONS NOW
ACKNOWLEDGING AEROSOL OR
AIRBORNE TRANSMISSION.
I THINK THERE ARE THREE MAIN
REASONS THAT IT'S TAKEN SO LONG.
SO, THE FIRST ONE IS ROOTED IN
HISTORY.
SO TRADITIONALLY, SINCE THE
EARLY 1900S, WE HAVE EQUATED
TRANSMISSION THAT OCCURS IN
CLOSE RANGE WITH DROPLET
TRANSMISSION.
AND WE DO KNOW THAT COVID
TRANSMISSION OCCURS MORE OFTEN
IN CLOSE RANGE.
THIS SORT OF BECAME -- SOME
PEOPLE REFER TO IT AS DOGMA.
EVEN WELL-ESTABLISHED AIRBORNE
DISEASES LIKE TUBERCULOSIS AND
MEASLES WERE ONCE THOUGHT TO BE
TRANSMITTED BY DROPLETS.
THERE'S A HISTORICAL BASIS FOR
THAT AND A DIFFICULTY IN
UPENDING THE STATUS QUO.
MEDICINE REQUIRES A -- WE WANT A
LOT OF EVIDENCE, WE WANT A LOT
OF DATA.
AND IN A FAST-MOVING PANDEMIC,
SOMETIMES IT'S HARD TO GATHER
ALL OF THAT.
AND I THINK WE ALSO OVER THE
LAST 18 MONTHS OR AT LEAST
INITIALLY WEREN'T NECESSARILY
HAVING THE DIALOGUE THAT WE
SHOULD HAVE BEEN HAVING WITH THE
AEROSOL SCIENTISTS AND THE
ENGINEERS.
SO, IT WAS MUCH HARDER TO SORT OF
GATHER THE EVIDENCE THAT WE
NEEDED.
AND THE SECOND REASON WOULD BE
THE SUPPLY QUESTION.
SO I REALLY DO THINK THAT AT THE
ONSET OF THE PANDEMIC, WE
CERTAINLY HAD ISSUES WITH SUPPLY
OF RESPIRATORS OR N-95 FOR
HEALTH CARE WORKERS.
WE DIDN'T AND WE STILL DON'T
HAVE ENOUGH ISOLATION ROOMS IN
HOSPITALS.
SO I THINK SUPPLY DICTATED SOME
OF OUR RELUCTANCE AS WELL TO
ACKNOWLEDGE AIRBORNE
TRANSMISSION.
AND THEN FINALLY, I THINK WE
NEED TO BE HONEST THAT IT'S MUCH
HARDER OR CAN BE SEEN AS MUCH
HARDER TO CONTROL AN AIRBORNE
TRANSMITTED DISEASE.
THE ONUS IS REALLY ON GOVERNMENTS
AND ON BUSINESSES TO PROVIDE
SAFE INDOOR AIR FOR THE PUBLIC
AND FOR EMPLOYEES.
IT'S A LOT EASIER TO JUST TELL
INDIVIDUALS TO WASH THEIR HANDS
AND STAY 2 METRES APART.

Steve says, HAVING SAID THAT, IF
PUBLIC HEALTH ORGANIZATIONS HAD
ACCEPTED THE NOTION OF AIRBORNE
SOONER, HOW MIGHT THINGS HAVE
BEEN DIFFERENT OVER THE PAST 20
MONTHS?

Text reads, What Could Have Been.

Dr. Addleman says,
YEAH.
I THINK WE WOULD HAVE HAD THE
TIME TO INVEST IN THE
TECHNOLOGIES THAT ACTUALLY WORK
TO MITIGATE AIRBORNE
TRANSMISSION AND THESE ARE HIGH
QUALITY MASKS, BOTH FOR HEALTH
CARE WORKERS AND REALLY FOR THE
GENERAL PUBLIC, VENTILATION, AND
THAT INCLUDES FILTRATION AS
WELL, SO HEPA FILTRATION UNITS,
AND EVEN SOMETHING LIKE UVGI,
WHICH IS THIS ULTRAVIOLET
GERMICIDAL IRRADIATION, WHICH IS
UNDERUTILIZED BUT HAS BEEN USED
FOR YEARS TO MANAGE TB AND IT'S
BEEN SHOWN TO BE QUITE
EFFECTIVE.
SO ONCE WE ACCEPT THE SCIENCE,
WE ACTUALLY KNOW WHAT THE TOOLS
ARE THAT WORK TO MITIGATE
AIRBORNE TRANSMISSION, BUT THEY
DO REQUIRE BOTH ACKNOWLEDGING
AIRBORNE TRANSMISSION AND THEN
INVESTING IN THESE TECHNOLOGIES,
AND UNFORTUNATELY, OUR RELUCTANCE
TO ACKNOWLEDGE AIRBORNE
TRANSMISSION MEANT THAT WE'VE
HAD A SIGNIFICANT DELAY IN
REALLY GOING FORWARD WITH THESE
TECHNOLOGIES.

Steve says, IF WE ACCEPT
AIRBORNE TRANSMISSION, DOES THAT
MEAN THE 2-METRE DISTANCING RULE
WE'VE BEEN TOLD TO KEEP BETWEEN
US AND THE NEXT CLOSEST PERSON
TO US, DOES THAT MEAN THAT RULE
IS POINTLESS?

Text reads, Keeping Your Distance.

Dr. Addleman says,
NO, IT'S CERTAINLY NOT
POINTLESS.
AGAIN, THAT'S WHERE THE
CIGARETTE SMOKE ANALOGY IS
USEFUL.
IF YOU'RE STANDING CLOSE TO A
SMOKER, YOU'RE GOING TO INHALE A
LOT MORE OF THAT SMOKE OR A LOT
MORE OF THOSE AEROSOLS THAN IF
YOU'RE STANDING FURTHER AWAY.
SO DISTANCE IS STILL IMPORTANT,
BUT IT'S NOT ENOUGH.

Text reads, All for Naught?

Steve says, THE PLEXIGLAS THAT
LITERALLY THOUSANDS OF ONTARIO
BUSINESSES HAVE BEEN USING TO
SEPARATE CLIENTS FROM THEIR
WORKERS OR OTHER CLIENTS FROM
EACH OTHER, ARE THOSE COMPLETELY
USELESS AS WELL?

Dr. Addleman says,
AGAIN,
I WOULDN'T SAY THEY'RE
COMPLETELY USELESS.
I THINK FOR DROPLET TRANSMISSION
AND, YOU KNOW, AT THIS POINT WE
KNOW THERE'S AEROSOL
TRANSMISSION.
WE SUSPECT THERE'S DROPLET
TRANSMISSION AS WELL.
SO, THEY WILL BE USEFUL
PREVENTING DROPLET TRANSMISSION.
THE PROBLEM IS THAT I THINK WE
HAVE RELIED ON THEM AT THE
EXPENSE OF INVESTING IN BETTER
MITIGATION TOOLS SUCH AS
IMPROVED VENTILATION, AND THERE
IS SOME EVIDENCE FROM AEROSOL
SCIENCE AS WELL THAT AEROSOLS
CAN UNFORTUNATELY BUILD UP SORT
OF IN THAT SPACE BEHIND THE
PLEXIGLAS.
SO, THEY CAN GIVE US FALSE
REASSURANCE AND IN SOME CASES
THEY MAY ACTUALLY UNFORTUNATELY
INCREASE AEROSOL TRANSMISSION.

Steve says, IN WHICH CASE, LAST
QUESTION HERE: WHAT ELSE?
YOU MENTIONED VENTILATION.
WHAT ELSE NEEDS TO BE DONE AT
THIS STAGE OF THE GAME TO
PROTECT PEOPLE MORE FROM THE
AEROSOL AS OPPOSED TO DROPLET
TRANSMISSION?

Text reads, Safeguards.

Dr. Addleman says,
I THINK THE FIRST THING THAT
WE NEED TO DO, WHICH IS ACTUALLY
FREE, IS TO DISSEMINATE THIS
INFORMATION IN A VERY CLEAR WAY
TO THE PUBLIC.
I THINK THAT MOST PEOPLE WANT TO
TAKE THE RIGHT STEPS TO PROTECT
THEMSELVES AND THEIR FAMILIES,
AND IF WE CAN HAVE A SHARED
MENTAL MODEL, AND THAT MENTAL
MODEL IS AIRBORNE TRANSMISSION,
THEN I THINK THAT THERE ARE A
LOT OF THINGS THAT INDIVIDUALS
CAN STILL DO TO MAKE SAFER
CHOICES.
BUT I DO THINK WE NEED TO TAKE
THE ONUS OFF INDIVIDUALS AS WELL
AND TALK ABOUT WHAT THE
GOVERNMENT AND WHAT BUSINESSES
NEED TO BE DOING TO PROTECT US
BETTER.
SO WE NEED A MORE ROBUST SUPPLY
OF GOOD MASKS, EITHER
RESPIRATORS OR N-95S.
THESE PROVIDE BETTER PROTECTION
FOR THE PERSON WEARING THE MASK
AS WELL AS SOURCE CONTROL, FEWER
AEROSOLS LEAKING OUT FROM THE
MASK AND SO YOU'RE PROTECTING
THE PEOPLE AROUND YOU AS WELL.
WE HAVE CANADIAN-MADE
RESPIRATORS NOW.
WE NEED TO SCALE THIS UP AND WE
NEED TO DISTRIBUTE THESE AND
EXPLAIN TO PEOPLE HOW TO WEAR
THEM AND WHEN TO WEAR THEM.
THE SECOND, AS YOU MENTIONED,
TECHNOLOGY IS VENTILATION.
OPTIMIZING VENTILATION IS NOT
SOMETHING WE CAN DO OVERNIGHT.
WE SQUANDERED A LOT OF TIME.
THERE ARE STILL IMPROVEMENTS
THAT CAN BE MADE.
WE HAVE TO RECOGNIZE THE FACT
THAT THIS IS CERTAINLY MORE
CHALLENGING AND MORE
RESOURCE-INTENSIVE.
WE CAN, HOWEVER, IMPROVE
VENTILATION THROUGH FILTRATION,
AND YOU PROBABLY HEARD A LOT OF
TALK RECENTLY ABOUT PORTABLE
HEPA UNITS OR AIR PURIFIERS.
ONTARIO HAS PUT THESE INTO A LOT
OF SCHOOLS.
AND THESE ARE REALLY USEFUL.
WHAT THEY DO IS THEY FILTER OUT
THE AEROSOLS THAT ARE IN THE
AIR.
THEY'RE QUITE EFFECTIVE.
THEY NEED TO BE SIZED TO THE
SPACE.
SO, PUTTING A SMALL ONE IN A
LARGE GYM IS -- YOU KNOW, MIGHT
HELP A LITTLE BIT BUT IT'S
CERTAINLY NOT GOING TO BE
ENOUGH.
BUT THAT'S ANOTHER TOOL THAT WE
CAN USE.
AND THEN FINALLY, AS I MENTIONED
BEFORE, THERE'S UVGI, WHICH IS
UNDERUTILIZED IN WHICH, AGAIN,
CAN'T BE ROLLED OUT OVERNIGHT
BUT WHICH IS SOMETHING THAT I
HOPE THAT WE CAN BE LOOKING INTO
MORE AND INVESTING IN MORE.
THIS UNFORTUNATELY MIGHT NOT BE
THE LAST VARIANT AND PROBABLY
NOT THE LAST AIRBORNE PANDEMIC.

Steve says, OH, DEAR.
THAT'S DR. SARAH ADDLEMAN
JOINING US FROM THE NATION'S
CAPITAL WITH SOME ENCOURAGING
NEWS AND SOME NOT-SO-ENCOURAGING
NEWS.
THANK YOU, DR. ADDLEMAN.
GOOD TO HAVE YOU WITH US ON TVO
TONIGHT.

Dr. Addleman says, THANK
YOU SO MUCH.

Text reads, Produced by: Harrison Lowman @harrisonlowman

Watch: How COVID-19 Is Airborne