miasmatism

Miasma theory was a historical explanation for disease that attributed illness to harmful vapors, or miasmas, arising from decaying organic matter, sewage, and stagnant water. This theory was widely accepted from antiquity through the 19th century and significantly influenced public health policies and urban planning in Europe, Asia, and beyond.12

The term "miasma" comes from the Greek word for "pollution" or "contamination." Ancient physicians observed that diseases often occurred in areas with poor sanitation and foul odors, leading them to believe that noxious air caused illness. This idea was prominent in ancient Greek writings, including those associated with Hippocrates, and persisted through the Middle Ages and early modern periods.13

While miasma theory encouraged environmental cleanliness and sanitation efforts, it was eventually disproven by the development of germ theory, which identified microorganisms as the cause of many infectious diseases. Despite being scientifically invalid, miasma theory played a crucial role in the historical development of epidemiology and sanitation.12