Ah, so we're making progress! You admit that it may in fact be dust that is causing discomfort rather than some unknown, unverified "fumes" that you don't have a shred of evidence for other than your personal incredulity.
Now, as DGM said, you have offered no information as to the context of the picture. You don't appear to even know who took it (or at least you have not indicated so in this thread). How, may I ask, do you draw the conclusion that they are reacting to "fumes" rather than dust swirls from a gust of wind blowing across what was at the time a very dirty, very dusty site? Occam's Razor would seem to lean toward the more mundane explanation of dust blown around by the wind, yet you go for the one that is quite literally impossible to verify, since none of us were there and it would be difficult if not impossible to contact the people in that picture, since there are few distinguishing characteristics visible in the photo.
If you do possess information on who took the picture in question, please provide it and/or contact the individual and ask them what the context was of the photo. What were the firefighters doing at the time of the photo being taken? Were they in some kind of formation that was disrupted by the dust swirls? Or was the photo taken much later after the ceremony was complete and that is why they were in what is colloquially known as a "gaggle"? Was the ceremony in any way disrupted by the dust swirls? Either provide this information, or admit that you don't know enough about the context of the photo to claim it is proof of ANYTHING, much less your putative "fumes".