I am just very curious if anyone else uses the ancient concept of Miasma theory in their games in any way?

Night Air, miamas, humours, -- the entire way of thinking about disease and illness prior to modern science establishing the existence of bacteria and viruses and so forth. They were why we say say something after sneezing and some other superstitions, because the spirits would get to you.

I used this as an underlying basis for several things recently, and while figuring out how to do something with a particular request, I hit upon expanding my own use of them as the underlying basis for things as varied as skeletons, zombies, golems, and now even a variant of warforged that is specific to my setting.

In short, I divided them up into five categories: Miasma, Humour, Vapour, Pneuma, and Zyme (because I am odd that way) and each has particular aspects to it -- but now they are officially planar beings in my cosmology and the "cause of many a varied thing".

Anyone else, or am I being too obscure for here?