Some general ideas from me.
Boiler houses. Remember those Fred Dibnah programmes where he toppled the chimneys?
Railway works. Did he transport old steam locos or carriages?
A boss where I used to work died of mesothelioma, attributed to asbestos dust from brake linings so I agree with the post about workshops.
General demolition contractors.
Water utility companies. I picked up a load of muck the other day and found an asbestos water pipe.