Yumako-
Yes, anyone in downtown breathed in a load of horrible air that day - and perhaps other things.. that dust..it haunts me still. And there are many who say that when the wind chnaged and blew alot of the worst air for the next 12 hours to Brooklyn, that they actually bore the brunt of the first worst air. Certainly, there were many animals in Brooklyn, stuck in apartments with open windows, that got sick or even died from that smoke. Noone really talks about that, but on The Well there are pet owners and neighbors of pet owners that posted about it.
But what the study refers to is long-term exposure to that air and all the toxins released when the building came down and by the fires that burned for a month. And that is indeed much, much worse for the people living within a half-mile of Ground Zero, and of course the rescue workers and others working at the site.