This article focused on the Cholera outbreak experienced in
Golden Square, an area in Central London, in the late summer of 1854. This
incident has become significant in that it is now a milestone in Public Health
and Epidemiology, or the study of incidence, distribution, and possible control of diseases and
other factors relating to health, as represented by the removal of the handle
on the Broad Street Pump. This was the result of John Snow’s conclusions that
the water consumption from that pump was the source of the outbreak. He came to
these conclusions using maps and scientific observations.
Snow originally encountered Cholera in 1831 during his
apprenticeship as a surgeon-apothecary and in dong so created an initial theory
that Cholera was a disease that was strictly in the gut and that it was the
direct result of fluid loss. Snow eventually was presented with a golden
opportunity to test his theory when the outbreak happened in 1853-1854. He did
so by conducting research by investigating each home that experienced a
mortality from Cholera, ultimately noticing that the centralized location of
the deaths was near the Broad Street Pump using a spot map, using bars to
decipher each mortality at that home (Figure 1). Later after Snow’s
investigation, the Board of Health created a similar graph after learning of
other deaths with improved location accuracy (Figure 2). Snow also eventually re-framed
his dot map to represent the improved location accuracy and accurate mortality
documentations.
The article, in conclusion, notes that Snow didn’t
necessarily use a map to discover the source of the outbreak, but rather
thought geographically. The text notes in the ending paragraphs that “the mere
act of seeing data arranged graphically in space yields no new understanding
without the support of a pathological theory.” (Brody et all, 68) Snow’s map demonstrating data
arranged spatially of what he had investigated - because he had a pathological
theory - does yield a new understanding as he stated that Cholera was a disease
of the gastrointestinal tract. As time moved forward and as it continues to do
so, a recurring theme appears of Snow being one who was a “clear-eyed modern
thinker who saw the facts” and in turn caused the removal of the Broad Street
Pump which halted the outbreak altogether.
While Snows findings were of great importance, I find it interesting that though he did not actually use a map to come to his conclusions, the story remains, that he did.
ReplyDeleteI find it interesting that he was smart enough to go around to each home and keep track of how many people had died. This was one step closer towards GIS, in that we are now able to have population maps, income maps, and so on and so forth. He was doing by hand what a computer is able to do now.
ReplyDeleteSnow's imaging is incredible, and it is wonderful that we get to see what he visualized so long ago. I find it interesting that he could come to a conclusion of the source without having technology to track it for him.
ReplyDelete