# Miasma From *μίασμα*, Ancient Greek: "pollution" > A theory that had considerable currency during the 18th and 19th centuries as a way to explain the origin and propagation of some epidemic diseases, particularly cholera. The theory was that the cause was miasma, an ill-defined emanation from rotting organic matter. The theory derived empirical support from the observed distribution of malaria and yellow fever in marshy regions, until it was discovered that these are mosquito-borne diseases. > [[last2007DictionaryPublicHealth|Last, J. M. (2007). A dictionary of public health.]] - Tied to early believes about cholera, chlamydia, the Black Death. Before waste management infrastructure was implemented, the streets of 19th century London were a breeding ground for disease. Horses were the primary transportation method, and could produce as much as fifty pounds of waste a day.[^1] Human waste was collected in chamber pots, and deposited outside in cesspools.[^2] Between a combination of horse and human waste, public health officials at the time believed that disease outbreak were caused by the smells, and not the waste material leeching into local below-ground water supplies. [^1]: [[PredictionX- John Snow and the Cholera Outbreak of 1854 (edX and HarvardX)]] [^2]: [[PredictionX- John Snow and the Cholera Outbreak of 1854 (edX and HarvardX)]]