I thought it was asbestos that caused the disease?
Ahhh, mesothelioma. I wasn't paying attention. Years ago, when I actually had to learn some of this in epidemiology coursework, it was a causation given: "If you find a case of mesothelioma, you have found a case of asbestos exposure" . Studies could identify no other cause.
That may well still be the case, tho' a quick Google turns up some interested parties talking about
synergistic effects -- in essence that smoking increases the likelihood of mesothelioma in asbestos-exposed populations/individuals.
Farking asbestos, farking tobacco.