Just the tons of asbestos worn out of brake shoes/pads over the years, not to mention hammered out of buildings might have a wee effect. Other chemicals and toxins abound in an area where humans have lived in large numbers for decades or even centuries.
Of course, it is far easier to blame having seen someone smoke a cigarette, or having smelled on once, than do some decent medical research into real occupational or other hazards. That would require historical, engineering, chemical and other research, and extensive knowledge of those icky dirty "blue collar" things most exhalted physicians would never consider messing with, and in an historical contest to boot. The horror.
When I go, if of lung cancer, the cigs will probably get the blame. Not the creosote fumes from building seawalls, not the granodiorite dust from drilling shot holes in the Blue Ridge, nor the welding smoke from working in a steel fabrication plant. Not the fumes from oil-based drilling mud or crude oil, the years of grey skies in summer while the Clintons burned off hundreds of thousands of acres of National Forest (yes, the smoke made it here, and quite noticeably), not the dust of the farm fields carrying the residuals from nuclear tests in the 50's or pesticides or herbicides.
Nope, gotta be the smokes.
Besides cigarettes are obvious, cigarettes are "stinky", and they come in bright colored easy to blame packages. They are even put out by one of the eeeevil "Big"s......yadda, yadda, yadda....
Jees, I am not a researcher but it seems it has a lot to do with luck. Perhaps it is as simple as breathing in a toxin on a bad day, when the immunity is a little low and for whatever reason a cell goes a little awry...and the foundation begins.