Miasma theory of disease

The miasma theory of disease held that diseases like cholera were caused by a miasma (Greek language: "pollution"), a noxious form of "bad air".

The miasma theory was consistent with the observations that:

• disease was associated with poor sanitation (and hence foul odors) and that
• sanitary improvements reduced disease,

but not with the observations of microbiology that led to the germ theory of disease.

Although incorrect, the miasma theory helped motivate major improvements in sanitation.

Prominent supporters of the miasma theory included:

• William Farr
• Florence Nightingale

External links

• Prevailing theories before the germ theory (http://www.ph.ucla.edu/epi/snow/1859map/cholera_prevailingtheories_a2)