William Firth Wells and Mildred Weeks Wells

Episode Transcript
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Speaker 1 (00:01):
Welcome to Stuff You Missed in History Class, a production
of iHeartRadio. Hello, and welcome to the podcast. I'm Tracey V.
Wilson and I'm Holly Freight.

Speaker 2 (00:16):
Before we start our episode today, a couple of folks
have asked us where they can buy shirts and things
because we used to have a T shirt store.

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Yeah, and then it went away.

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Uh and the reason for that is just that iHeartRadio
moved that they didn't. They were already with a different
T shirt vendor than we had been with when iHeart
acquired us, and so eventually we needed to all be
on the same thing. Uh. So our T shirt store
now is at Cottonbureau dot com. You can either go

(00:49):
to cottonbureau dot com and search for stuff you missed
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com slash people slash stuff you miss in history class,
with each of those words separated by a dash. Personally,
it seems easier to me to just go to Cottonbureau
dot com and use the search function, but you do

(01:10):
you Right now, we have coffee mugs, tope bags, cell
phone cases, stickers, and T shirts. Our prior T shirt
vendor was the creator of a lot of our previous
T shirt designs. So right now what we've got is
stuff with our logo on it, but in the future
we may have some other designs also kind of working

(01:31):
on that behind the scenes. Just wanted to let everybody
know in case you either have looked for a shirt
recently or have just wondered, do they have T shirts
and stuff? Now we do again Cottonbureau dot com, and
now we can start the episode. A couple of weeks ago,
I was listening to an episode of the podcast ninety
nine Percent Invisible, and this episode was called Airborne. It

(01:56):
was an interview with Carl Zimmer, who wrote Airborne, The
Hidden History of the Life We Breathe. I have not
read this book. I did use it to confirm some
details biographically about the people that we were talking about today,
but I cannot comment on the book as a whole.
What I can comment on is that over the course

(02:17):
of this episode I got progressively more frustrated because they
were talking about some research that sounded like that least
in theory that could have really lessened the impact of
the COVID nineteen pandemic. But this was not like new
research from after the pandemic started. It was from the
nineteen thirties and forties, So as I was listening to this,

(02:41):
I jotted down a couple of potential podcast topics for
our show as I was listening and getting mad about it.
One was nineteenth century chemist Max von pet and Kulfer,
who I knew sounded familiar but had forgotten that we
already did an episode on We will have that episode

(03:02):
as our next Saturday Classic. And the other thing I
wrote down was today's topic, which is husband and wife
team William Firth Wells and Mildred Weeks Wells. Their research
had the potential to make a really big difference in
the safety of the indoor air, but that research did
not really have that kind of impact on public health.

(03:24):
And just to note, this research did involve some experiments
on animals.

Speaker 1 (03:30):
Mildred Weeks was born in eighteen ninety one to William F.
Weeks and Mary Alice Denton Weeks. She was born in
what's now Oklahoma, then it was called Indian Territory, and
she had an older sister named Marian. We don't really
know a whole lot about Mildred's early life, but it
seems like things may have been difficult for her and

(03:50):
her sister, even though they were from a prominent family, so.

Speaker 2 (03:54):
That explanation goes back to before her parents, William and
Mary Alice, were mayor married. The girl's great grandfather, John B. Denton,
was the namesake of the city and County of Denton, Texas,
and then his son, Their grandfather, Ashley Newton Denton, was
an actor who was appointed superintendent of the Texas State

(04:15):
Lunatic Asylum. The asylum bookkeeper was the girl's future father,
William Weeks. Denton and Weeks were both accused of mismanaging
the asylum's funds, and Weeks was eventually charged with embezzling
somewhere between one thousand and fifteen hundred dollars.

Speaker 1 (04:35):
Both men maintained that they had not done anything wrong.
One newspaper write up of Weeks's arrest said that quote
his numerous friends here assert that while he was careless
in business matters, he will explain out of it. These
allegations don't seem to have affected Denton's opinion of Weeks, though,
since he presumably gave his permission for his daughter Mary

(04:57):
Alice to marry him in eighteen eighty, which was right
In the middle of all of this.

Speaker 2 (05:03):
William was exonerated in eighteen ninety and the family went
to Indian Territory, which, as we said, is where Mildred
was born. But rumors continued to follow William, and eventually
he seems to have kind of disappeared. Mary Alice died
when Mildred was only ten, and Mildred and her sister
Marian were raised primarily by their grandmother, who lived in Austin, Texas.

(05:28):
Mildred earned a bachelor's degree from the University of Texas
Medical Branch in nineteen eleven. She earned her MD from
the University of Texas at Austin in nineteen fifteen, where
she was one of only three women in a class
of thirty four. She moved to Washington, d C.

Speaker 1 (05:45):
And got a job studying bacteria at the Public Health
Service Hygienic Laboratory. While working at the lab, she met
William Firth Wells.

Speaker 2 (05:54):
William Firth Wells was born in Boston, Massachusetts, on August
twenty fifth of either a teen eighty six or eighteen
eighty seven. I found both those years. His parents were
Obadiah F. Wells and Helen Davis Wells, and he was
one of their four children. We don't have a lot
of detail about his early life either, but he studied

(06:15):
bacteriology at the Massachusetts Institute of Technology.

Speaker 1 (06:19):
He graduated from there in nineteen o nine. After graduating,
he eventually made his way to Washington, d c. To
become a sanitary bacteriologist for the Public Health Service, a
few years before Mildred also started working there. Mildred Weeks
and William Firth Wells got married in nineteen sixteen, and
a year later they had a son, William Junior. They

(06:42):
called him Bud. We also don't have a whole lot
of detail about Bud, but it seems as though he
was disabled or he had some kind of mental illness.
He always lived with family until being institutionalized, which happened
after Mildred's death, and at that point he was in
his forty.

Speaker 2 (07:01):
During World War One, William Senior was drafted and joined
the Sanitary Corps, serving both stateside and in Europe and
attaining the rank of captain. His work before, during, and
after the war was largely focused on water contamination and
water borne illnesses. He studied how diseases could be spread

(07:22):
through the water and how salmonella typhi, which causes typhoid fever,
could grow in oysters. He developed filtering techniques to purify
river water so that it would be drinkable, and chlorination
methods to clear bacteria out of oyster beds. After the
end of World War One, the Weekses moved to New York,

(07:43):
where william had gotten a job with the state's Conservation commission.
He continued working with oysters, including developing methods to artificially
propagate them and repopulate depleted oyster beds. Inspired by machines
that separated cream from milk, he developed a centrifuge that
could separate oyster larvae from the water so that they

(08:04):
could be raised in tanks and then returned to the
Long Island Sound. This combined with his earlier sanitation and
water quality work to ensure that these oysters would be
safe to eat once they were harvested. By nineteen twenty five,
Williams's work with oysters was being hailed as almost miraculous.

(08:25):
The Association of Fisheries Commissioners and the National Association of
Oyster Growers and Dealers held a celebratory dinner on October
first of that year with artificially propagated oysters on the menu,
and this whole thing was praised in newspapers.

Speaker 1 (08:43):
Two years later, an Associated Press write up on William's
work described the oysters that he was growing as super oysters.
He moved from the New York State Conservation Commission to
a higher paying job with an oyster company, but then
in October of nineteen twenty, the stock market, of course crashed,
which is marked as the start of the Great Depression.

(09:06):
The oyster company was sold and William lost his job.

Speaker 2 (09:10):
William tried to make ends meet by writing and consulting,
and Mildred got a job working with the International Committee
for the Study of Infantile Paralysis, also known as polio.
Polio had been on the rise in parts of the
world since the late nineteenth century, and it was widely
feared and not completely understood. Karl Landsteiner and Irwin Popper

(09:34):
had confirmed that polio was infectious, and they had concluded
that it was caused by a virus in nineteen oh eight.
Doctors also had a sense that polio could be spread asymptomatically,
but once they were able to isolate the actual virus,
they didn't usually find evidence of it in people. Who
were not experiencing symptoms, so they didn't really understand exactly

(10:00):
how the virus was spreading. Outbreaks often happened in large waves,
usually in the summer, but the patterns of cases within
those outbreaks could seem almost random. Mildred Wells was part
of a project to systematically evaluate all of the research
that had been done on polio and to produce a

(10:20):
comprehensive work on the subject. That work was published in
October of nineteen thirty two as Poliomyelitis a Survey made
possible by a grant from the International Committee for the
Study of Infantile Paralysis. This was primarily funded by philanthropists
Jeremiah Millbank. Other than Millbank's forward and a preface by

(10:41):
doctor William H. Park, this book was written entirely by women.
The first chapter, historical summary, was by Elizabeth F. Hutchin,
and the remaining chapters were all by women. Mds Helen Harrington,
Josephine B. Neil, and Mildred Weeks Wells. Well wrote the
chapter on epidemiology. Several modes of transmission had been proposed

(11:05):
for polio, including direct transmission through respiratory droplets, milk water,
insect bites and fomites. When she started working on this project,
insect transmission had been generally rejected, and the most widely
accepted theory was droplets. Droplets were believed to be able

(11:27):
to travel only a short distance, meaning that people had
to be in close contact to spread droplet born diseases.
This idea grew from the work of German microbiologist Carl Fluga,
who had done research primarily focused on tuberculosis in the
late nineteenth and early twentieth centuries. He was building on
earlier work which had already demonstrated that coughs and sneezes

(11:51):
could carry infectious particles that could settle on things like clothing, bedding,
and handkerchiefs. Fluga did things like placing microscopes at varying
distances from tuberculosis patients, finding that the slides closest to
the patients collected the largest respiratory droplets with the most basilli,
while the ones farther away had much smaller droplets with

(12:14):
very few beecsillai. So through this findings were way more
complex than this, and a lot of them were specific
to tuberculosis. He hadn't test studied other diseases. In whether
they worked the same way at all. But a lot
of doctors took away from this that diseases were spread

(12:34):
through droplets, and droplets didn't travel very far and settled
out of the air quickly, so close contact was required
for most disease spread, and airborne spread at a much
greater distance was not really a big concern. One such
doctor was Charles Chapin, Health Officer of Providence, Rhode Island,

(12:54):
and author of the nineteen sixteen public Health manual The
Sources and Modes of Infection that was regarded as a
landmark text in the field. This work stressed the role
of droplets while minimizing the idea that there was much
danger from airborne pathogens that could travel longer distances. Under
the heading actual Danger of Infection by air, Chapin wrote, quote,

(13:19):
pathogenic bacteria may withstand drying and the pulverization of the
dried material, and they may actually be found floating in
the air. Yet they may not, after all, be dangerous,
either because they have holly or partially lost their virulence,
or because there are too few in number, or for
some other unknown reason. Mildred weeks Wells's research into the

(13:43):
epidemiology of polio didn't line up with what was known
about droplets. She described polio's seasonal recurrence as difficult to
reconcile with droplet transmission. At one point, she wrote, quote, certainly,
poliomyelitis as we ordinarily encounter it in the United States
does not behave epidemiologically in accordance with the concepts that

(14:08):
have become crystallized as to how a contagious disease should behave.

Speaker 1 (14:14):
She then quoted from a nineteen thirty one paper by M.
Greenwood titled on the Statistical Measure of infectiousness quote, an
illness is held to be catching when it has usually
been possible to explain the existence of a case of
it by close association with an immediately pre existing case.
The notion of more or less infectiousness depends on some

(14:36):
appraisement of the proportion of persons attacked to persons exposed
to the risk of attack.

Speaker 2 (14:43):
So polio was weird. It seemed to be catching, and
yet it did not fit that description of catching because
people who caught it often didn't have a history of
close contact with another polio patient. Wells wound up concluding
that polio was similar to other airborne or droplet infections,

(15:05):
but that people seemed to have a higher innate resistance
to it than to diseases like smallpox or measles, possibly
because people became immune to polio after being infected but
without developing clinical symptoms. Today, polio is known to be
transmitted through droplets and aerosols and through fecal contamination, which

(15:28):
the research Mildred was working with really did not think
was the case, so she wasn't completely on the right
track for thoroughly explaining the epidemiology of polio, but this
did lead her to thinking about ways that disease might
travel through the air. Mildred's and William's work came together
after this, which we will get to after a sponsor break.

(15:59):
William birth Wells's work with oysters led him to the
use of centrifuges to separate oyster larvae from fluid. Mildred
Weeks Wells's work on polio led her to think about
airborne disease spread. Those two things came together in nineteen
thirty when William found another full time job working at

(16:20):
Harvard doing research and teaching sanitary science. This job paid
a lot less than he had been making working for
the Oyster Company, but the Great Depression was still going
on and the Wellss really needed the money. At Harvard,
William Wells developed a machine, the Wells Air Centrifuge, that
could separate bacteria, dust, and other contaminants from the air

(16:44):
the way that he'd separated oyster larvae from seawater. He
also developed a nutrient medium to use in the centrifugees
collection tubes so that any bacteria from the air would
be able to grow so that he could then analyze it.
At a request of the Commonwealth of Massachusetts, he used
this centrifuge to study the safety of the air in

(17:05):
textile mills in Townslake Fall River, Lawrence, Lowell, and New Bedford,
where the air was full of textile dust and also
artificially humidified. Wells eventually brought on assistance for this and
other work, and those were brothers Richard and Edward Riley.
In nineteen thirty four, William Wells intentionally introduced bacteria into

(17:28):
one of the air conditioning systems at Harvard and then
used his centrifuge to collect air samples and track where
all the bacteria went. That same year, he did an
experiment during one of his lectures. He used the centrifuge
to sample the air at the beginning of class, and
then he introduced some sneezing powder into the machine's exhaust.

(17:51):
As it spread, the student started sneezing, and he collected
another sample of the air. He collected another sample after
some more time had passed, and then a final sample
after class was over and the students had left the room.
He compared each of these samples, finding the largest number
of normally occurring respiratory bacteria and the samples that had

(18:14):
been taken sometime after the students had started sneezing, but
there were also still bacteria in the sample that he
took after the class was over. Mildred was also part
of this research, although she was not officially hired at
Harvard until nineteen thirty five, and even then she wasn't
paid a salary. A lot of their work was collaborative,

(18:36):
with both of them deeply involved, but Mildred was the
one who wrote most of.

Speaker 1 (18:40):
The papers and lectures. Much of their published work was
published under both of their names.

Speaker 2 (18:47):
Their research strongly suggested that some bacteria could travel more
than just a short distance, like in a droplet and
could stay in the air and stay viable for a
long time, building up in the air of a room
the longer people were in their breathing it. But when
they took the center views outdoors, their samples yielded few,

(19:09):
if any viable bacteria.

Speaker 1 (19:11):
These findings were summed up in a patent application a
few years later. Quote Ordinarily, the droplet and nuclei are
so rapidly dispersed in the outside air that there is
but little danger of infection thereby. In crowded or poorly
ventilated spaces, however, they constitute a real menace. Even well

(19:31):
ventilated buildings are not free from this danger, particularly where
the same air after conditioning is recirculated so as to
be used over and over again for breathing. For such
recirculation merely adds to the bacterial concentration of the recirculated air.

Speaker 2 (19:49):
While a lot of their colleagues were really skeptical of
their work, William and Mildred became convinced that diseases could
be spread through the air beyond just most close contact
from droplets, and they started experimenting with ultraviolet light as
a way to stop it.

Speaker 1 (20:07):
As with William's work with oysters. This got some media attention.
On July thirtieth, nineteen thirty six, the Decatur Daily Review
ran a photo of Wells with his research equipment at
the Harvard School of Public Health, and it ran under
the headline scientists fight flew germs with violet ray. He
was working on an experiment that involved funneling influenza infected

(20:31):
air to a ferret enclosure. The vents carrying the air
to some of the ferrets were treated with UV light
while the other vents were not, and the ferrets getting
the UV treated air stayed healthy while the others got sick.
In November of nineteen thirty six, Mildred and Richard published
two articles in the Journal of the American Medical Association.

(20:54):
One was titled Airborne Infection and the other was Airborne
Infection Sanitary Control. Airborne Infection detailed the Wells's conclusion that
there were two types of airborne disease transmission. There were droplets,
as previously described by Carl Fluge. These were larger than

(21:14):
zero point one millimeters in diameter. These quickly fell from
the air due to gravity, But droplets smaller than zero
point one millimeters in diameter could stay aloft, and as
they were aloft, they evaporated, leaving behind only the droplets
infectious nucleus, which could stay in the air even longer

(21:37):
and travel much farther than droplets could. A graph of
the relationship among gravity, evaporation and how long infectious material
can stay in the air is known as the Wells curve.
They also concluded that the number of bacteria in the
air quote correspond to the degree of contamination by the occupants,

(21:59):
and they can compaired this to waterborne intestinal illnesses. People
were being exposed to diseases carried through the air, including influenza, pneumonia, bronchitis, colds,
and measles, over and over in a cycle that would
continue until the whole population was finally immune to whatever
the illness was. But if people were experiencing the same

(22:22):
number of intestinal infections by repeated exposure to waterborne illnesses, quote,
that would condemn a water supply as being highly dangerous.
They went on to say, quote, it might be concluded
on epidemiologic grounds that the atmospheres of our common habitations
are even more highly infective airborne infection. Sanitary Control reported

(22:46):
on experiments conducted in the tunnels under Harvard Business School,
which tested the susceptibility of airborne pathogens to ultraviolet light.
The most dramatic reductions of bacteria in the air were
within five feet of UV light source, but there was
still a measurable difference as far as fifty five feet away.

(23:08):
They concluded, quote air purification methods that depend on filtration
or sedimentation may be more effective against dust an ultraviolet
rays may be more effective against nuclei, the two being
complementary and therefore effectively combined. In nineteen thirty seven, the
Washington d c. Evening Star noted the Wells's work, although

(23:32):
without mentioning Mildred. This write upset in part, quote doctor
William Firth Wells is the trapshooter of the scientific world.
For five years he has been gunning for the flu bug,
dropping it with an ultraviolet ray. This write up went
on to call the project a quote scientific cleansing of
workaday breathing air, which will vastly lessen casualties from nose

(23:56):
and throat diseases.

Speaker 2 (23:58):
That same year, William Firth Wells and Mildred Weeks Wells
were fired from Harvard. William had been hired even though
he didn't have an advanced degree, and on top of that,
he is not described as a very good teacher, giving
ponderously boring lectures and caring only about his research, not
his classes.

Speaker 1 (24:19):
But a bigger.

Speaker 2 (24:20):
Issue seems to have been that he and Mildred both
developed a reputation for being really hard to work with,
including being crabby and argumentative. Some frustration is understandable here,
given that a lot of their colleagues just seemed really
dismissive of their work, but the Wells is also apparently

(24:40):
argued with people who were on their side and with
people whose opinion of them really mattered, like their boss,
Gordon Fair, professor of sanitary engineering. Fair apparently thought he
should be credited on the Wells' publications as well as
named on the patent application that came from their work.

(25:01):
That was US Patent two one nine eight eight sixty
seven Method and Apparatus for Preventing Infection, which we read
from earlier. That patent was awarded in nineteen forty not
only with Fair's name on it, but with Fair listed first.
William and Mildred both seemed to have fought with Fair
over this credit issue, and according to some accounts, Mildred

(25:23):
was more aggressive about it, but it's also really hard
to take that at face value since people's perceptions of
her would have been influenced by social expectations for women
to be polite and unassertive. Yeah, was she really being
aggressive or did people just think she was aggressive because
she wasn't being meek? Also, she was doing work and

(25:45):
not getting paid for it right and handing over the
credit to men. Uh. It took some effort for them
to find a new employer, which we will get to
you after a sponsor break. After being fired from Harvard,

(26:09):
the Wells's next move was to Philadelphia, where the University
of Pennsylvania had established an airborne infection laboratory. This included
paid positions for both William and Mildred. While Mildred was
being paid about a third of what William made even
though she had an MD and he had a bachelor's degree,

(26:31):
their combined salaries were more than William had been making
at Harvard. In nineteen thirty eight, William and Mildred published
Measurement of Sanitary Ventilation in the American Journal of Public
Health that began quote ability to modify man's environment is
not confined to enhancement of comfort, convenience, or even safety,

(26:53):
but extends to the prevention of disease and the promotion
of health. By supplying pure water and pure food, the
sanitary engineer has in many communities almost eliminated intestinal infection.
Is it unreasonable to hope that when airborne infection is
better understood, diseases conveyed through the respiratory tract may likewise

(27:15):
be reduced through the provision of pure air supplies. This
paper presented multiple possible configurations for using UV light to
reduce the number of pathogens in the air. One was
using UV light to treat the air within a ventilation
system before circulating that air back into a room. That

(27:37):
could be the most useful and small crowded spaces like
train cars. In large rooms, there was a lot more
space and a lot more air, making that kind of
ventilation treatment inefficient. The UV lights at the time had
the potential to cause eye damage, so treating the whole
room was most easily done in scenarios like operating rooms

(28:00):
where there was a high need for infection control, and
also all the people in the or could reasonably be
expected to wear eye protection. Other possibilities included things like
light barriers, like a curtain of UV light that would
separate hospital wards from each other. There were equations for
the bacterial reduction that could be expected with each of

(28:22):
these different setups. From there, the paper expressed a hope
that this kind of research could be correlated with epidemiological
data quote this may lead to a realization of our
present hope that if the sanitary quality of air is controlled,
reduction of respiratory disease will be accomplished. William had invented

(28:44):
what he called an infection machine, which could be used
to expose animals to air that was laden with viruses
or bacteria. By nineteen forty one, William had used this
machine to demonstrate that tuberculosis, influenza, and strep could all
be transmitted to animals through the air, and that treating
that air with UV light could prevent those infections. Meanwhile,

(29:09):
Mildred was working on a practical experiment that had started
at Germantown Friends School in nineteen thirty seven. UV lamps
installed in some of the classrooms seemed to reduce the
number of measles cases during an outbreak at the school.
There were about ten times fewer measles cases in the
classrooms with the lights than the ones without them. Mildred

(29:31):
published Ventilation in the Spread of Chicken Pox and Measles
within school Rooms in nineteen forty five, which detailed these findings.
Not all of their experiments were that effective, though. In
nineteen forty two, UV lights installed in the town of
Swarthmore seemed to stop one outbreak of mumps, but it

(29:53):
didn't have much of an effect on another one. The
weeks As speculated that there might be a seasonal factor
to this. The lights seemed to work in the winter
when the air was dry, but not in the summer,
when it was humid. They speculated that this humidity might
affect how well the lights worked, and that that might
also be connected to the seasonality of some illnesses. During

(30:16):
World War Two, William advised the War Department on protections
for soldiers living in crowded camps and barracks. He and
Mildred were both concerned about something like the nineteen eighteen
flu pandemic happening again. But while there was some limited
use of UV lights at military facilities, the military's attention
just seemed to be focused elsewhere, and this really frustrated William,

(30:40):
especially when he later learned that the army had been
focused on airborne disease transmission when it came to the
idea of germ warfare, just not when it came to
protecting soldiers from ordinary illnesses. William and Mildred's marriage also
seems to have fallen apart, at least partially during this period.

(31:01):
Their maid left her job, and it's likely that the
maid had been doing some of the caregiving work for Bud.
Mildred resigned from the Airborne Diseases Lab in nineteen forty four.
Each of them did projects on their own or with
other collaborators rather than together.

Speaker 1 (31:19):
After this.

Speaker 2 (31:20):
That includes Mildred's nineteen forty five paper that we mentioned earlier,
which was published with only her name.

Speaker 1 (31:27):
William worked with Herbert Ratcliffe on a tuberculosis study which
concluded that only very small particles could get deep enough
into the lungs to cause that disease. He also worked
with his former assistant, Richard Reiley, now a researcher in
his own right, and a new assistant, Kretel C. Mills,
on an experiment at the Baltimore Veterans Administration. This involved

(31:50):
three hundred guinea pigs which were exposed to air from
the rooms of tuberculosis patients. Half of the guinea pigs
got air that was treated with UV light, and the
other half got air that was not. All of the
guinea pigs getting UV treated air stayed healthy, while about
three a month in the other group developed tuberculosis.

Speaker 2 (32:12):
Mildred worked with the New York State Department of Health
trying to replicate the results of their earlier research with
UV lights. They started with an experiment in central schools
that were located in rural areas, based on the idea
that these students mostly saw each other only at school,
without a lot of crowd exposure from outside of school,

(32:34):
like a student would probably get if they lived in
a city.

Speaker 1 (32:38):
This experiment had mixed results. The classrooms that had UV
lights did seem to have a different pattern of disease
spread During a measle's outbreak. A few students at a
time got sick over many weeks in the UV treated classrooms,
while lots of children all got sick almost simultaneously in
the untreated classrooms, But the total number of students who

(33:02):
got measles was not that different. One possible complicating factor
in this experiment was that the children rode buses to school,
and those buses did not have UV lights. Mildred also
worked with William Halla to install UV lights in as
many places as possible in Pleasantville, New York, so that

(33:22):
it could be compared to nearby Mount Kisko, which did
not have the lights. They published a paper on this
in nineteen fifty titled Ventilation in the Flow of Measles
and Chicken Pox through a Community. Beyond installing these lights
weeks in Halla figured out all of the children's susceptibility
to measles and chicken pox based on their past history

(33:45):
so that they could factor that in to their disease
risk calculations, and they did contact tracing for each new
case in each of the towns. The results of this
study were also mixed. Pleasantville had a measles out break,
but it hit during a rainy spring, and the Wellses
had already published that their UV lights were not as

(34:06):
effective in high humidity. And it also seemed like even
though there were no UV lights installed in Mount Kisco,
its whole population was partially protected by the irradiation program
that was going on in Pleasantville. It basically cut off
one of the possible sources for an illness to be
introduced into Mount Kisco. Meanwhile, William was writing a book

(34:29):
called Airborne Contagion and Air Hygiene, An Ecological Study of
droplet infections. It was published in nineteen fifty five after
many years of work. It was more than four hundred
and fifty pages long, and while he had really hoped
that it would serve as the definitive work on airborne
infections and air sanitation, this book was really not a success.

(34:54):
As we have said, Mildred was the better writer. She
had written a lot of her stuff before this. She
did not work on this book with him. Mildred Weeks
Wells died on February twenty third, nineteen fifty seven, at
the age of sixty five. William Firth Wells died on
September nineteenth, nineteen sixty three, at the age of seventy six.

(35:18):
Both of them had experienced serious health issues in the
last years of their lives. Mildred's sister Marian, tried to
take over Bud's care after Mildred's death, but she was
also in her late sixties by them, and as we
mentioned earlier, ultimately Bud was institutionalized.

Speaker 2 (35:36):
William Firth Wells's guinea pig study in Baltimore was still
going on when he became too sick to work. After
his death, Mills and Riley finished the work and published it.
Mills also contracted TB, but she recovered with treatment. This
research definitively demonstrated that tuberculosis could be airborne and led

(36:00):
to the development of the Wells Riley equation, also called
the Wells Riley model, which is a way to calculate
the probability of being infected by an airborne pathogen. William
Wells's name was not included on the final publication of
this work, though Riley later wrote an article about this
in which he described that omission as his eternal shame.

(36:25):
So Mildred Weeks Wells, and William Firthwells studied airborne disease
transmission for more than twenty years. They showed that a
lot of diseases could be spread through aerosolized particles rather
than just large droplets, and that some larger droplets had
the potential to evaporate into much smaller particles. They also
demonstrated that UV light could potentially reduce the number of

(36:48):
pathogens in the air and thus the number of illnesses
at least in some scenarios. But while there were some
other researchers who did experiments to replicate their work in
the nineteen forties and earth nineteen fifties, this didn't lead
to a huge rethinking of airborne disease transmission and its prevention,
especially in public settings. The Wells's work had more influence

(37:11):
on studies of the physics of particles spread through the
air than on public health. To be clear, the widespread
adoption of the kinds of UV lights that the Wellses
were using probably would have caused other issues, including skin cancer,
especially if those lights were shining on people rather than

(37:33):
being used within air circulation systems. But it seems like
if their work had gotten more favorable attention, we might
today be living in a world where illnesses that are
spread through the respiratory system are less frequent and less
widespread than they are today. Like we might not be
living in a world where it's just sort of taken

(37:55):
for granted as inevitable that there is a cold and
flu season, and this of course also applies to COVID.

Speaker 1 (38:03):
There's some speculation around why their work didn't get that
kind of attention. One possibility is just William and Mildred's
reputation for being hard to work with, which made people
just not want to. Another is that when they first
started their research, the world of medicine was still trying
to distance itself from the idea of miasmas as agents

(38:24):
of disease. William and Mildred absolutely were not describing things
as miasma's. They were talking about actual pathogens being spread
through the air. But it's possible that there was just
some innate resistance to the idea of revisiting the air
as a source of contagion. During and after their lifetime,
some of the diseases they studied became preventable through vaccines

(38:47):
or treatable with antibiotics, which also may have made large
scale projects to clear pathogens from indoor air just kind
of seem less urgent.

Speaker 2 (38:56):
Simultaneously, it seems like a conflation or oversimplification of ideas
in the Wells work may have contributed to standards that
did eventually emerge in the field of infectious disease and
public health, but standards that have some real limitations. One
is an idea that diseases can be spread as droplets

(39:19):
or as aerosols, and that there's a five micron threshold
forming a dividing line between these two things, with most
illnesses on the droplet side of that line. That played
a huge part in the public health messaging about COVID
in twenty nineteen and twenty twenty, when organizations like the

(39:40):
World Health Organization and the Centers for Disease Control really
emphasize the idea that COVID was droplet based, not aerosol
or airborne.

Speaker 1 (39:51):
That droplet guidance led.

Speaker 2 (39:53):
To things like the social distancing guideline of six feet
apart or one or two meters depending on where you live,
and a very big focus on hand washing and surface sanitizing.
It was not until more than a year into the
pandemic that both of those organizations acknowledged that COVID could
be airborne, meaning aerosolized particles could travel a lot farther

(40:16):
and stay in the air longer than droplets could. Washing
your hands and cleaning things is still very important. It
leads to reducing the spread of other diseases we've talked
about on the show, like neurovirus, but with COVID, a
really big thing is just not breathing in virus laden air.

Speaker 1 (40:39):
A paper titled how did we get here? What are
droplets and aerosols? And how far do they go? A
Historical Perspective on the Transmission of Respiratory infectious Diseases was
published in twenty twenty one. It looked at gaps in
the understanding of airborne disease transmission and how those gaps
affected public health policies during the early pandemic in a

(41:01):
way that was confusing and ineffective. This paper traces the
idea of the five micron threshold to multiple concepts from
Wells's work that all got kind of mashed together. The
idea that droplet and airborne transmission both existed depending on
the size of the particle, and that particles measuring between
one and five nanometers could penetrate deep enough into the

(41:24):
lungs to cause tuberculosis. Conflating those ideas led to a
different idea entirely, which has some parallels to what happened
with the work of Carl Fluga, which we mentioned earlier. Meanwhile,
in the context of COVID nineteen, specifically, far UVC lights
started making headlines as a kind of new and novel

(41:46):
way to possibly fight the pandemic in early twenty twenty one,
and this has continued to be reported on in more
recent months. Some articles on this acknowledged that uv light
has been known to kill mike organisms for roughly a century,
but far UVC has not really been framed as like

(42:06):
a refinement of something that the Wells is we're using
sometimes with really promising results back in the first half
of the twentieth century, that is William Firth Wells and
Mildred Weeks Wells. Do you also have a little bit
of listener mail? I do?

Speaker 2 (42:26):
This is from Aaron and Aaron's email is titled Chronologue
Yes with four s's and two exclamation points, community science
advocacy listener mail, which I love the excitement of that title.
Aaron wrote, are you allowed to write listener mail about
another listener mail? I squealed when I heard the listener

(42:47):
mail at the end of the July Unearthed Part two.
I work for a land conservancy in northern Lower Michigan
and we use Chronologue to track restoration sites that our
nature preserves. It's an invaluable tool for us and a
really easy way to contribute to community science data aggregation.

(43:07):
We have a relatively small team for the area. We
serve thirty eight people for a service area the size
of Delaware, and only ten of them are land stewards.
I cannot stress enough the importance of community science. Data
from I Naturalist, E Bird Journey, North Nature's Notebook and
Chronologue are used in our stewardship plans, restoration, site management,

(43:30):
invasive species tracking, communications, storytelling, and fundraising. Community science is
the quickest, easiest, cheapest, and in my opinion, most fun
way to get involved with your local land trust organization.
Thanks to you both for the amazing podcast. I love
your obvious passion for telling everyone's history from a fair
and neutral stance. The infinite fun facts I use to

(43:52):
annoy my husband are just a bonus and now some
pet adjacent tax for your time at work. We employ
two herds of miss and or retired dairy goats to
help us battle an ongoing problem with the invasive shrub
autumn olive. We also own and manage a farm where
we manage a herd of belted galloway cattle as a

(44:13):
demonstration tool for regenerative agriculture methods. I have attached a
few photos of each stay weird erin man Aaron I
love this email. I love these pictures of these cows
so cute goats, also cute using goats for invasive plant management.

Speaker 1 (44:30):
Also love that.

Speaker 2 (44:33):
By coincidence, this weekend, I was on a hike in
one of my local green spaces, and I am not
sure if they were using Chronologue or another service, because
I forgot my phone at home, and I was fine
hiking without my phone because my watch can also make

(44:56):
a phone.

Speaker 1 (44:56):
Call in the event of an emergency.

Speaker 2 (44:59):
But that meant that when I got to a thing
I had never seen before, which was about helping them
track the spread of an invasive plant, which was a
similar like put your phone on this stand and take
a picture, I could not see whether they were using
Chronologue or some other some other service to do that,
so I will have to go back by there at

(45:20):
some point and find out. Thank you again, Aaron for
this great email and these adorable pictures of delicious, delicious
vegetation being munched up by goats. If you would like
to send us a note about this or any other podcast,
we are at History Podcasts at iHeartRadio dot com, and

(45:41):
you can subscribe to our show on the iHeartRadio app
or wherever I like to get your podcasts. Stuff you
missed in History Class is a production of iHeartRadio. For
more podcasts from iHeartRadio, visit the iHeartRadio app, Apple Podcasts,

(46:02):
or wherever you listen to your favorite shows.

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