Early chlorine disinfection and waterborne epidemiology
Desinfección con cloro y epidemiología del agua (Londres)
- Date
- 1850-1854 · confidence medium
- Place
- London (Soho, Broad Street), England, United Kingdom
- Credited to
- John Snow (epidemiology, 1854); Semmelweis (chloride of lime, 1847); John Snow and William Budd (chlorine disinfection)
- People
- 👤 Ignaz Semmelweis1818–1865👤 John Snow1813–1858👤 William Budd1811–1880
- Field
- Life & health
⚠️ Disputed: the sources disagree.
What it is
Snow demonstrated with his map of the Broad Street cholera cases that the disease was spread by contaminated water, and together with Budd proposed disinfecting water supplies with chloride of lime. The origin of modern epidemiology and chemical water treatment.
Continuous chlorination of the public supply did not arrive until 1897-1908; in 1854 Snow proved the waterborne theory, and Semmelweis had been using chloride of lime for handwashing since 1847.
What it led to
- The Metropolis Water Act (1852) and compulsory filtration
- Systematic chlorination (Maidstone 1897, Jersey City 1908)
- Epidemiology as a cartographic and statistical science
- The end of cholera epidemics in Western Europe
Built on
- Discovery of chlorine (Scheele, 1774) and bleaching powder (Tennant, 1799)
- James Simpson's slow sand filter (Chelsea, 1829)
- Statistical maps
Made possible
- London main drainage system1858-1865
- Chlorination of drinking water
- London sewerage system
- Public-health statistics