bmrdude (or anyone else who'd like to respond),

I've heard that you can use a standard cotton air filter (like you get at the hardware store for putting up insulation) sprayed lightly with lysol as temporary protection in the event of a bio attack. Since this would be cheap and field expedient, it would be very useful if its true.

Since your an expert on this, in your opinion, is there any truth to this claim?

Thanks in advance,

Ben