>"The black lungs of heavy smokers I would weigh once, then squeeze under cold running water for fifteen minutes until they became baby pink and tripelike, and then weigh again: the difference in the two figures, often a couple of pounds or more, was the weight of the tar and nicotine that quite possibly was the killer." A few pounds ? If you'd asked me, I would have guessed the weight of lung-accumulated smoking gun…
Modern LA is orders of magnitude safer than London in the '60s and earlier. Those conditions would have been comparable to some parts of China today.
Pittsburgh was a city of coal-heated homes and coke-powered blast furnaces set in river valleys, and in the '60s and earlier was dark at noon:
http://www.buzzfeed.com/kevintang/stunning-photos-of-pittsbu...
Many of the older brick-and-stone buildings are still covered in black stains.