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Chloera Changed everything

Starting in the 1830s, Cholera pandemics swept the United Kingdom. Nobody knew how the disease was transmitted. Germs were not an established idea. One London doctor- John Snow, tried to find out how the disease spread, and today, one of his investigations is iconic in the field of epidemiology, and it all centered on a pump. John snow made a map to prove his solution to the cholera mystery in London. It also shows the confusio

n and the problems he was up against. The disease often killed half the people who got it- it caused vomiting and diarrhea; the rapid loss of fluids was fatal. Many people believed cholera was transmitted in a "miasma" Imagine an evil cholera cloud, a map in the 1840s shows cholera "mist" that was blamed for transmission. Snow suspected a different source. At the time, people usually didn't get water directly in their homes. It came from a neighborhood pump connected to one of the few water companies in the city. John snow mapped different water companies in the city, service areas in London. You can see how they are occasionally separate and overlapped. If a standard pump was contaminated at any point- at the source or near the pump, snow believed that the pump could kill people. In 1849, he wrote that in his study of symptoms and specific cases had led him to suspect that "emptying sewers into the drinking water of the community." caused outbreaks, not a miasma. Five years later, he had a chance to prove it and stop a fresh outbreak in the process. In August 1854, 20 people lived at 40 Broad Street, including an infant who died of cholera. After her death, snow started to investigate the outbreak. He didn't think the original water source was the problem, but he thought something might be wrong down the line. At the pump, he took samples of the water. They seemed clean, but he wasn't satisfied. Because more people were getting sick, he asked questions up and down the street, Where one man had noticed a bad smell from his water. Snow asked the registrar for a list of people who had died. He started going house by house to interview the survivors, and many of the dead had taken water from the pump. He became convinced the broad street pump was the common link among the dead. He wrote, "I had an interview with the Board of Guardians of St. James Parish on the evening of Thursday 7th September, and represented the above circumstances to them.

In consequence of what I said." The handle of the pump was removed on the following day. People stopped using water. However, the snow had not won yet. The newspaper reported the streets were covered in lime; the city was using it as "a powerful disinfectant on the streets. That showed they were not entirely convinced the pump was the problem. They still suspected miasma. Snow bolstered his case through investigation and recording. He learned the 18 workers who died at this factory had drunk from big barrels of water drawn from the pump. At the same time could serve as proof of snow's theory according to the Miasma theory. This place would have been covered in cholera clouds affecting all workers, But snow learned the workhouse had it as well no bad water got in. The same went for the brewery. That's because snow learned the workers there drank from the brewery's water supply or, more likely, only drank the free malt liquor they got on the job. That's right; drinking on the job saved their lives. Snow strengthened his arguments and his map. He adjusted the location of the pump to show how close it was 40 Broad Street and drew a dotted line- he showed a zone where it would be closest to walk to the Broad Street pump, rather than another one. That zone is where most people died. He tabulated every death, by date, to do it. This was paired with a local Reverend’s  similar data-driven investigations. A local surveyor looked at the plumbing at 40 Broad Street, where the Infant had died. He learned that Cesspool, where sewage collected, was poorly designed and lines with decaying bricks when the Infants diapers have been washed, the cholera-carrying the water had leaked into the Broads Street pump supply. John Snow passed away in the 1858. His obituary reads, “Dr John Snow: The well- known physician died at noon, on the 16th instant, at his house in Sackville street, from an attack of apoplexy. His teachers' pm chloroform and other anaesthetics were appreciated by the profession and other anaesthetics were appreciated by the profession.” At the time, Snow was more famous for stuff like chloroform Inhaler than a map. It took years for the “ Investigation of John snow” to become an example of subsequent to become an example for subsequent outbreaks and epidemiology textbooks,and it slowly, eventually, helped end the miasma map of a city. It is a map of his process and the field it shaped. It gace direction to a world where disease did not have to be hidden in a cloud. Instead it could start from a pump 


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