does pipe tobacco have additives Buy Good Stuff 6-oz Red Online Pipe Tabacco and Cigarette Tabacco:

We recommend adding a few drops of e-liquid directly to the coils, allowing it to soak into the fresh wick

Underlying mechanisms for such outcomes occur through multi-faceted interaction among flavoring agents and respiratory epithelium, and isolated compounds such as cinnamaldehyde and diacetyl are recognized for cytotoxic and inflammatory actions 8

If you cant see the mold it may be in the walls, in which case call your local health department or a home inspector (the American Society of Home Inspectors website provides listings based on area code), to find the problem

They are actually specific manufacturing processes