On 31 August 1854, a major outbreak of Cholera occurred near Broad Street in Soho District of London, England. Physician John Snow couldn't convince other doctors and scientists that contaminated water(specifically from BroadStreet pump), not air, was the source of outbreak. His dot map plotting deaths and pumps in Soho District strongly supported his statement.
This project is recreation of the visualizations for 1854 London Cholera Outbreak based on data created and compiled by Robin Wilson (robin@rtwilson.com, www.rtwilson.com/academic) - Jan 2011 | 1851 UK Census Data (http://www.visionofbritain.org.uk/)
Tools Used
The application has been written using R. Shiny has been used as the web interface for it.
Libraries used: ggplot2, DT, leaflet, lubridate, reshape2, shiny, shinydashboard, grid, jpeg
Visualization
The application can be navigated through the sidebar which consists of three Visualizations namely: 1854 Cholera Outbreak, Cholera Fatalities Maps and 1851 UK Census Data.
1854 Cholera Outbreak: Tables and Charts showing the Fatalities of 1854 London Cholera Outbreak
Cholera Fatalities Maps: Maps displaying the locations of 1854 Cholera Fatalities
1851 UK Census Data: Tables and Charts showing the 1851 UK Census Data
All the colors that have been used are color blind safe.
Application has been developed for desktops and can also scale to size of 4080 by 2304.
Navigation Sidebar of the application
1854 Cholera Outbreak
● You can compare the data from the table showing Cholera fatalities on each day with the chart which provides an abstract view of the overall scenario of Cholera fatalities.
● The table headers are color coded with the line colors for resemblance.
● The number of deaths for a given age group on the basis of sex is shown in a table and comparison can be made of the number of Male and Female fatalities in particular age group from the bar chart.
Charts and tables showing the data for 1854 Cholera Outbreak in London
Cholera Fatalities Maps
● The left map represents the Cholera Death locations on the original London Soho district. The size of the bubble represents the number of deaths and crosses are the pumps in the area.
● The map on the right represents the Cholera Death Locations on the John Snow's original map. The more denser/darker the color is, more the number of deaths. Hovering over the death locations shows the actual number of deaths.
Maps showing death locations of Cholera fatalities
1851 UK Census Data
● The first column represents data for Number of Men by Age Group. The color density corresponds to the number of men. More men, more darker is the color and vice-versa.
● The second column represents data for Number of Women by Age Group. The color density corresponds to the number of women. More women, more darker is the color and vice-versa.
● The charts in the first two columns provide a comparison and overview of the population distribution by Sex.
● In the third column the table can be used to get the exact number of men and women.
● The pie chart in the lower right provides percentage of men and women.
1851 UK Census Data
Findings
1854 Cholera Outbreak
● Maximum number of attacks(143) occurred on Sep,1. And the pump handle was removed on Sept, 8. The number of attacks on Sep, 8 were 12. Even though the pump handle was removed about a week later from Sep,1 the attacks had already declined by about 91%.
Reports | John Snow's beliefs:
"There is no doubt that the mortality was much diminished, as I said before, by the flight of the population, which commenced soon after the outbreak; but the attacks had so far diminished before the use of the water was stopped, that it is impossible to decide whether the well still contained the cholera poison in an active state, or whether, from some cause, the water had become free from it."
Number of deaths declined even before the pump handle was removed
● From the map it can be seen that most of the deaths are clustered around the area of Broadstreet Pump which is now-a-days the BroadWick Street.
Reports | John Snow's beliefs:
"On proceeding to the spot, I found that nearly all the deaths had taken place within a short distance of the [Broad Street] pump."
Maximum number of deaths around BroadStreet Pump Location (areas marked in circle's)
● Some larger bubbles can be seen away from the Broad Street Pump and closer to other pumps.
Reports | John Snow's beliefs:
Reports have stated that deaths situated closer to other street pumps were mainly because people preferred the water of the Broad Street pump to that of pumps which were nearer, or children went to the school near the pump in the Broad Street.
Areas away from BroadStreet pump(shown in circles) with large number of deaths due to preference for BroadStreet pump water
● Some areas near the BroadStreet Pump suffered minimum Cholera Attacks. Two of the anomalies were: Broad Street Brewery and Work House.
Reports | John Snow's beliefs:
According to the reports people in the Brewery had access to free beer, so they didn't drank water and moreover they had their own water supply. The WorkHouse also had their own well.
Marked areas represents those with minimum fatalities despite their proximity to BroadStreet water pump.
● Most of the people who contracted cholera belonged to the age group of over 80.
People over the age of 80 constituted most of the Cholera fatalities
1851 UK Census Data
● 1851 UK population consisted of 51% females and 49% males.
Pie chart showing population distribution on the basis of sex
● 25% of the total population are children with ages 0 to 9. Whereas, only 0.5% of total population constituted people with age above 80.
● In most of the age groups the number of females are more than the number of males.
Table and Plots show the distribution of population of different age groups and gender