During the tuberculosis outbreak of the 1900s, many believed in miasma theory*, the belief that sickness is caused by bad air and pollution. The idea was promoted by Edward Trudeau, a doctor from New York who was infected with tuberculosis and, after moving to the Adirondacks, noticed an improvement in his condition. He began spreading the news that fresh air and nature were a cure.
Upon hearing this, thousands of Americans moved west in search of better health, and many campaigns for western expansion were targeted toward “health seekers.” People infected with tuberculosis migrated in large numbers with pioneers and explorers.
A Glasgow street, 1868.
Credits:Science Museum/SSPL
*In miasma theory, 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. That a killer disease like malaria is so named - from the Italian mala‘bad’ and aria ‘air’ - is evidence of its suspected miasmic origins.
In 19th-century 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, an observation that lent weight to the theory.
The germ theory of disease emerged in the second half of the 1800s and gradually replaced miasma theory. Although it had been disproved and rejected, the miasma theory’s existence was not without its merits. By removing the causes of bad smells, reformers often inadvertently removed bacteria, the real cause of many diseases.
