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ALYSSA GOODMAN: In 1854, cholera struck the city of London.
Over 600 people died in just a few weeks.
Physician John Snow is often credited with discovering
that cholera is a waterborne disease and with ending the 1854
epidemic by removing the handle from the contaminated Broad Street Pump.
The full story is much more interesting.
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So I've been reading about the John Snow Pub for years.
There it is.
Look at that.
Right here, on what used to be Broad Street, is this fine-looking pub.
There's this very inauspicious sign.
It says here, "The Red Granite kerbstone," over there,
"marks the site of the historic Broad Street
Pump associated with Dr. John Snow's discovery in 1854
that Cholera is conveyed by water."
So that's a really simple summary of the whole John Snow story.
And to give you just an overview, here's the story.
So it's 1854.
It's really hot and the end of the summer in London.
We're here is Soho, which was a very crowded neighborhood filled
of tenements with people not of a lot of means.
And there were a lot of people crammed into these buildings--
many, many people to an apartment.
And it's hot, and it's sweaty.
And the part that you can't imagine, looking right now-- because it's still
pretty crowded; it's not that hot, but it's still pretty crowded-- here,
the street now is completely clean.
We see street sweeping vehicles.
We see drainage in the streets.
We have sewers.
None of that was true in 1854.
Instead, the people who lived in these buildings, some of them
had cesspools in these little front courtyards.
And they would take their human waste and other waste
and just kind of throw it out the window into the cesspool
or bring it down to the cesspool.
And then it would drain wherever it drained.
And the street-- whoa-- was not something
that you could easily walk on and keep your feet clean.
Wow, that's slippery and disgusting.
And so people were used to this kind of somewhat disgusting ambiance.
And people thought that when there were terrible outbreaks of disease,
especially cholera, that it was caused by the very poisonous air
at this miasma, that they called it.
And the smell from all the poo and all the animal waste was pretty horrible.
And it was a pretty sensible theory to think
that that could be causing disease.
But John Snow, who lived not far from here--
we'll go there later-- was a physician in London,
who was convinced that cholera, in particular, was a waterborne disease.
It was not carried in this smelly air.
And what happened here on this spot in 1854
was that there was a baby who lived at number 40 Broad Street, which
would have been just about here, baby Lewis, who came down
with some sort of terrible disease that caused really terrible diarrhea.
And I think pretty quickly, people realized that it was cholera
and that there was going to be another outbreak of this very terrible disease.
And people started dying.
So what happens?
What happened was the waste from baby Lewis and other people
who became ill with the cholera-- so human vehicle matter--
mixed with the water supply that was in a relatively shallow well.
I think it was about 20 feet down under the street right here.
And then the cholera bacteria began to multiply.
And then people would ingest the water, which
provides the human intestines a place where the bacteria multiplied fast.
They need a host like that.
So anyway, when people ingest this contaminated water,
they come down with cholera from which you die in the hours to days.
And John Snow, who really was looking for a place
where he could, unfortunate circumstances as they were,
have a very concentrated outbreak of cholera
where he could study the origins of the outbreak,
was interested in helping the people but also interested immediately
in collecting information about what was going to happen in this outbreak.
So he would have come over here to this neighborhood
and started canvassing all the people around here to see who was dying
and who needed help and what they had done to possibly ingest water
from the various water supplies in the area.
And right here, at a location right near this red kerbstone,
was a source of what was apparently some very clean-tasting-- sweet-tasting,
actually, water for drinking.
Right here, it's called the Broad Street Pump.
And it turned out, as he started canvassing the neighborhood,
that he realized that most of the people who had fallen ill
and who were continuing to fall ill had drunk water from the particular pump.
So there were other water problems in the neighborhood.
And one of the things that we'll see later
is that, in the end, when he put all these data together and he made a map,
he had to show that this pump by walking was the closest to almost all
of the people who eventually died-- 600-something people died
in the epidemic.
So even though there are other pumps that are geographically
potentially nearer to those people, this one tasted good
and was close to the people who died by walking.
So in epidemiology today, it's known that one way to really make your case
is to have exceptions to the rules-- so people
who should have died, who didn't die, and then people who did
die for no apparent reason.
And so John Snow, in his work, actually found
both of those kinds of exceptions.
And so one case is what people sometimes refer to as the people who
were saved by the beer.
And so these were the brewery workers who worked a few blocks from here,
and drank mostly beer, and so had a clean supply of things to drink.
And the other case was the workhouse that was near here.
And these were the most indigent potentially people
in poorest of health.
And so why did they live?
They systematically survived this epidemic.
And part of the reason-- the main and the most important reason--
is that the workhouse had a well, had its own source of clean drinking water.
So there are the exceptions of people who should have died and didn't die.
And then what happened was he also found out
about a family who would bring water to a member of that family who
had moved far, a couple miles, outside of this neighborhood.
And they brought her some water, an elderly aunt.
And she and her niece drank it.
And those people both died.
So to us, looking at modern epidemiological methods,
John Snow had plenty of evidence to say that this water from this well
contained the contaminant that caused the disease.
But it still took actually many years until the locals believed his story.
And another thing that we should mention is that John Snow did not
collect all this data himself.
If you look around the street here, you'll
see that this is a very busy neighborhood
with lots and lots of people.
And I think it was even busier in 1854.
But it was a small contained community.
And there were people, for example like a curate, Henry Whitehead, who was
a local, who kind of knew everybody.
And so John Snow worked with Whitehead and with other people in the area
to really canvas the information and collect
the kind of sociological demographic information
that he needed to know who lived where, when they died, where they likely
got their water, who they talked to, who they came in contact with,
all kinds of other details about their personal lives.
And so that kind of human data collection,
in this tightly knit community, was also really, really important.
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