In 1831 a terrifying new epidemic arrived in London, bringing with it fear and panic—and a sense of urgency about the city's sanitation problems.
In the 1700s, Great Britain began transforming into an industrialised nation. By the 1800s, London was the largest city in the world as a result of the social changes brought about by industrialisation, such as mass migration from the countryside to the town.
But London was a city overwhelmed by the waste products of its ever-growing population, the majority of whom lived in the squalor of overcrowded slums. Human waste piled up in courtyards and overflowed from basement cesspits into the gutters and waterways.
In such conditions diseases were inevitable. Outbreaks of diseases such as typhoid and scarlet fever were common, but the arrival of cholera led to new investigation into sanitation and the causes of disease.
Cholera and sanitary reform
European doctors were not familiar with the symptoms and prognosis for cholera. They had no idea how the disease spread and there was no cure. The rapid onset of symptoms such as diarrhoea, nausea and vomiting resulted in dehydration from fluid loss, lethargy, erratic heartbeat, sunken eyes and dry and shrivelled skin with a characteristic bluish tinge.
The combination of scary symptoms and fear of the unknown seized the public’s imagination and chlolera was characterised as a foreign epidemic (it was commonly known as Asiatic cholera), which was 'invading' the nation.
The first appearance of cholera in 1831 was followed in 1837 and 1838 by epidemics of influenza and typhoid, prompting the government to ask the lawyer and leading social reformer Edwin Chadwick to carry out an enquiry into sanitation.
In his publication The Sanitary Conditions of the Labouring Population (1842), Chadwick used quantitative methods to show that there was a direct link between poor living conditions, disease and life expectancy. This investigation inspired the Public Health Act of 1848 and the establishment of the general Board of Health, of which Chadwick was the first director.
In 1848, The Times described cholera as 'the best of all sanitary reformers', and Chadwick was appointed to the first Board of Health and became the Sanitary Commissioner of London.
In the course of his investigations into the living conditions of the poor, Chadwick became interested in the problem of sanitation. He was convinced that active measures such as cleaning, drainage and ventilation would improve the health of working people and therefore make them less dependent on welfare.
Chadwick supported the rapid removal of human waste, seeing it as a major source of the 'bad air' that caused disease. Unfortunately, his limited improvements to the chaotic sewage and drainage systems led to a greater flow of raw sewage into the River Thames—the main source of drinking water for London. By further contaminating London's water supply, the risk of cholera was greatly increased.
The measures that Chadwick introduced were based on the medical thinking of the day, which attributed the spread of infectious diseases to foul smelling air, called miasma.
Miasmas versus contagions
Cholera was a new and exotic disease from Asia, and brought into sharp relief the two major theories of the time about the pattern and spread of infectious diseases.
In miasma theory, it was believed that diseases were caused by the presence in the air of a miasma, a poisonous vapour in which were suspended particles of decaying matter that was characterised by its foul smell. The theory originated in the Middle Ages and endured for several centuries.
The advocates of contagion theories believed that an infective agent was spread from person to person, which would explain why those who cared for the sick often fell sick themselves.
Measures to prevent and control the spread of infectious diseases were based on these two theories. Sanitation and good hygiene practices such as washing walls and floors, removing the foul-smelling sources of miasmas—decaying waste and sewage—were miasmatic measures.
Contagionist measures were those such as quarantine and restriction of movement, preventing direct contact with potentially infected people.
In practice, both types of measures were used. During the Black Death, infected houses were quarantined and strangers banned from entering towns, but at the same time, fires were used to destroy infected materials and people wore masks and nosegays to purify the air they breathed.
At the end of the 1800s, germ theory was able to account for both infection through contaminants in air and water and person-to-person contact but it still left unanswered questions—such as why, when two people were exposed to the same source of infection, only one might get the disease and the other appeared untouched.
In 1800s England, the miasma theory made sense to the sanitary reformers. Rapid industrialisation and urbanisation had created many poor, filthy and foul-smelling city neighbourhoods that tended to be the focal points of disease and epidemics. By improving the housing, sanitation and general cleanliness of these existing areas, levels of disease were seen to fall, and to provide evidence that apparently supported the miasma theory.
John Snow's theory of how cholera spread
In 1848–49 there was a second outbreak of cholera, and this was followed by a further outbreak in 1853–54. Towards the end of the second outbreak, John Snow, a London-based physician, published a paper, On the Mode of Communication of Cholera (1849), in which he proposed that cholera was not transmitted by bad air but by a water-borne infection. However, little attention was paid to the paper.
Following the third cholera outbreak in 1854, Snow published an update to his theory, with statistical evidence that he had collected from an area of London around Broad Street, Soho. By recording the location of deaths related to cholera in the area, Snow was able to show that the majority were clustered around one particular public water pump in Broad Street.
He eventually convinced local officials to remove the handle of the pump, although by that time the worst of the epidemic had actually passed. It was later established that a leaking sewer ran near the well from which the water was drawn.
Unfortunately, Snow failed to convince many in the medical establishment of his theory, including William Farr, who was responsible for medical statistics at the General Register Office. Farr took part in the General Board of Health's 1854 Committee for Scientific Enquiries on the cholera outbreak but although they accepted Snow's data, they dismissed his theory that the mode of transmission for cholera was waterborne.
Farr was finally converted to Snow's theory in the wake of the final London cholera epidemic of 1866. He produced a monograph which showed that mortality was extremely high for people who drew their water from the Old Ford Reservoir in East London. Farr's work was then considered conclusive.
London's sewage network
Over decades the River Thames had effectively become London's largest open sewer, but it wasn't until the Great Stink of the summer of 1858—when the smell of raw sewage in the River Thames caused Parliament to close—that Londoners decided to do something about the city's sanitation crisis.
Unable to ignore the stench of the Thames and fearful of the miasmatic belief that 'all smell is disease', parliament sanctioned one of the century's great engineering projects—a new sewer network for London.
As Chief Engineer on London's Metropolitan Board of Works, Joseph Bazalgette was primarily responsible for the creation of the new system. The new sewers made a huge difference to the health of Londoners and much of the system is still in use today. It also physically changed the appearance of riverside London and the River Thames.
London's rapid growth had not been accompanied by the infrastructure improvements needed to deal with the huge amount of sewage produced each day. Instead, it was contributing to waves of cholera outbreaks and other public health crises.
Bazalgette's engineered solution was a system that channelled the waste through miles of street sewers into a series of main intercepting sewers which slowly transported it far enough upstream so that it could be pumped into the tidal Thames—from where it would be swept out to sea.
Bazalgette insisted on constructing wide egg-shaped, brick-walled sewer tunnels rather than the narrow bore pipes previously favoured by Edwin Chadwick and others, which allowed the system to cope with the increasing volumes of waste. The new sewerage system was opened in 1865.
The following year cholera returned one final time. The victims of this outbreak were almost entirely confined to areas of East London not yet connected to the new sewers. These slum dwellers were left with little option but to drink contaminated water. The final outbreak both justified the expense of Bazalgette's sewers and provided further evidence for the waterborne transmission of cholera.
Suggestions for further research
- Royal College of Surgeons, Mapping disease: John Snow and cholera
- L Jackson, Dirty Old London: The Victorian Fight Against Filth, (London: Yale University Press, 2014)
- S Halliday, The Great Stink of London: Sir Joseph Bazalgette and the Cleansing of the Victorian Metropolis, (Cheltenham: The History Press Ltd, 2001)
- S Hempel, Medical Detective: John Snow and the Mystery of Cholera, (London: Granta Books, 2014)