Here in California, a number of houses have been converted into huge grow houses for weed.
Many people familiar with marijuana grow operations will wonder, just how the heck do they hide the stench of that many pot plants from the neighbors?
It is relatively easy as pointed out by a grower to whom I posed the question.
They use activated charcoal.
Activated charcoal is used in NBC suits, NBC filtration for safe rooms, and also as an antidote for acute poisonings. It is used to remove aerosols, poisons, organic vapors, biologicals and other noxious fumes from the air.
Now, this grower is cheap. I mean a real skinflint, so for him to spend any money whatever he spends it on has to work and be as cheap as possible.
He uses a number of cheap $20.00 box fans that have been duct taped to cardboard forms fashioned to hold a series of furnace filters. The set up is a pull rather than push air system.
He first uses a light density polyurethane foam mat he buys from an air conditioning supply house. He claims that the foam has a static charge to it and captures dust and other particles readily. It is washable and reusable.
I can attest to the fact that it does trap dust, and is washable and reusable. I use poly foam pre-filters on my own home heating system.
The next is a progressively more dense poly foam, to actively trap lighter dust particles. He explains that he needs to keep the possible contamination of his plants down. He actively seeks to remove mold spores, etc. with this filter.
The last stage is a carbon filter. He uses a common filter that is available at most hardware stores. Take a look at the ones offered on this website.
Then it dawned on me.
What he had done, on the cheap, was build a series of NBC filtration systems. Take a look at this page and pay attention to the description of the filter.
Granted, this isn't going to be something you'd want to risk your life on if you were at ground zero, but it gives you an idea of something to try in a worst case scenario, especially if you're on the outskirts of a disaster area.
After wandering around on the web, I found this neat how to: Fan In A Can Safe Room Squirrel Cage Fan. Then there's the "improved" Fan In A Can.
Combining these ideas may just work for you.