>>>I wonder how many asthma attacks every year because of the smoke?
>>
>>Fortunately, this year there was much less smoke than in previous years - still too much for my taste, though. I am not sure about the causes - perhaps a combination of more aggresive action by authorities, and the population gradually being educated through TV ads.
>
>I've often wondered what New York City was like in winters in the late 1800s.
>Or Boston or Chicago or Moscow or Oslo or...

Once in Leningrad in 1979 I counted the tall chimneys that I could see from my hotel room window. 52. It was end of winter, and maybe there were more, but this is how much I was able to see.