Reply #4: I don't know, maybe it's a hard question?

[0rganism]

There's a lot of different kinds of pollution, right? There's air pollution, groundwater contamination, radioactive waste, hell, even noise pollution counts for something. 3rd-world salvage operations on second hand computer equipment create massive amounts of hazardous pollution, but is it fair to lay that at the feet of IBM, Apple, and/or Dell? And how would you even begin to count gene pool contamination by the likes of Monsanto? What about raw resource extraction damage by timber and mining operations? All this makes it pretty tough to quantify, especially when so much of the damage is externalized in ways that are tough to measure to begin with and mixed into a generally degraded environment along with all the other muck generated by billions of humans all trying to get a piece of the "good life."

Phew. That was a bit more rantlike than I intended.

Anyway, just offhand I'd nominate DuPont, Dow, Exxon, GM and Alcoa. That's not research or anything, just an intuitive sense of the situation.

Hmm, I just looked it up, and it seems my intuition wasn't far off according to this index:
http://www.peri.umass.edu/Toxic-100-Index.430.0.html

All my nominees are in the top 20 according to this measurement. I missed some obvious ones: ADM and GE seem to be pretty blatant violators. It surprises me that Kodak and Bayer are so high up, though, and what's with Nissan? I notice steel companies are well-represented on the list -- I just don't usually think of them when I think pollution. Anyway, that's one way of getting at an answer. Good luck avoiding their products :D