John Snow & The Broad Street Pump

     


  The first comprehensive epidemiological study was undertaken by Dr John Snow, who analysed fatalities in the London cholera outbreak of 1854. By linking these to one water pump on Broad Street in Soho, London, he established that cholera was a water-borne disease. That summer had been hot and the people were drinking cold water rather than boiling it for tea, as was usual. 

         At once, Snow investigated and mapped the locations of the homes of those who had died in this outbreak. The pump central to his map was on Broad Street. Of the 89 people who died, only 10 lived closer to another pump. 

         In addition, Snow found that the water coming from the pump was cloudy; people had reported that it smelt bad in the days preceding the outbreak. The well was nine metres deep, but a sewer only seven metres below ground was just above it. On 7 September, a week after the outbreak began, Snow got the authorities to remove the pump handle. The number of infections and deaths fell rapidly. (Illustration of the contents of a pail of water sourced from a cistern, around the time of the 1854 cholera epidemic in the UK)

        A replica of the pump, with a memorial plaque and without a handle (to signify John Snow's action to halt the outbreak) was erected near the location of the original pump. Nowadays this pump is visited by many people.