I don't think he was saying that mold spores are always on tobacco. I think he was saying if the tobacco gets moldy, there will still be spores there no matter how much you clean it.
I think it is safe to say that there are spores on most tobacco, it isn't the spores that are of concern, it is active, growing, living mold. The spores themselves are dormant.
Everyone gets a little mold in their system, in food, inhaled, etc., all the time and the body just fights it off. But there is a fine line where the wrong kind of mold or too much is taken in where the body's defenses cannot handle, and an individual's health will vary greatly in how much a person can tolerate and fight off. If you've been sick or have had lung disease or illness in recent months, you are particularly susceptible.
I've never had moldy tobacco, and I don't recommend anyone smoking it, but if I ever get it, I guess I will have to make my own judgement call whether I think it can be saved and is worth it and how far along it is. If the visible mold can be removed and steps taken to kill any residual, well then . . . hmm. If I saved it, I'd only do so based on my limited background in chemistry and biology and mainly just as an experiment to see if I can beat it. I like a good challenge. Maybe the food for some future thread? Unless you are very sure though, just don't try.
I am not about to smoke any moldy tobacco, but why is it that the cigar guys do it quite often. Is it a different type of mold? And, if spores are always on the tobacco, as Woodsroad has said, then we are smoking mold spores all the time. Right?
No, don't EVER smoke anything that LOOKS moldy! As to cigars, what a lot of people do if they think they have mold and it hasn't penetrated the outer wrapper is wipe the spot with a damp paper towel first to remove the little plants, then spot treat with a little bleach. Or cut that part off. Anything left, if anything, is too little left to be of any danger. But you still have to watch the other nearby cigars and wipe out the humidor with 91% iso alcohol.
There are just a few main kinds of mold out there, 4 or 5, but no one kind that attacks tobacco only. If your stuff gets moldy, only a lab can be sure what kind.
And yes, we are all probably smoking (and inhaling) a little mold spore all of the time. Spores and dry, inactive mold are one thing, ACTIVE mold is another. The best way to deal with mold is to take away the conditions favorable to its growth in the first place. Cool and dry rather than damp and warm.