Bingley wonders Wouldn't a miasma imply something more physical than just a collection of odours? To me it implies something almost palpable like a mist or fog.
Yes, that's the way it's often used. The definitions I found are:
mi·as·ma (m-zm, m-)
n., pl. mi·as·mas or mi·as·ma·ta (-m-t).
A noxious atmosphere or influence: “The family affection, the family expectations, seemed to permeate the atmosphere . . . like a coiling miasma” (Louis Auchincloss).
A poisonous atmosphere formerly thought to rise from swamps and putrid matter and cause disease.
A thick, vaporous atmosphere or emanation: wreathed in a miasma of cigarette smoke.
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[Greek pollution, stain, from miainein, to pollute.]
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mi·asmal or mias·matic (mz-mtk) or mi·asmic (-mk) adj.
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Source: The American Heritage® Dictionary of the English Language, Third Edition
Copyright © 1996, 1992 by Houghton Mifflin Company.
Published by Houghton Mifflin Company. All rights reserved.
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miasma \Mi*as"ma\, n.; pl. Miasmata. [NL., fr. Gr. ? defilement, fr. ? to pollute.] Infectious particles or germs floating in the air; air made noxious by the presence of such particles or germs; noxious effluvia; malaria.
Source: Webster's Revised Unabridged Dictionary, © 1996, 1998 MICRA, Inc.
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miasma n 1: an unwholesome atmosphere; "the novel spun a miasma of death and decay" 2: unhealthy vapors rising from the ground or other sources; "the miasma of the marshes" or "a miasma of cigar smoke"
Source: WordNet ® 1.6, © 1997 Princeton University
