I do think that it's a good idea to do some research in the area, a really good idea. We've assumed far too much about the resiliency of our environment. With

I do think that it's a good idea to do some research in the area, a really good idea. We've assumed far too much about the resiliency of our environment. With that said, I would be quite surprised if unspecific metal debris/dust is going to have any major effects, except as it already is as a threat to the functionality of satellites, space stations, and rockets. The meteorite argument is quite strong, but not unassailable, as meteorites in general has a chemical composition that is quite different from space hardware. Not that we use a lot of Antimony in rockets, but it works as en example. If I interpreted the numbers correctly, we can put an upper limit on the contribution of atmospheric Antimony from 78000 tons of meteorites at ~16 kg, or roughly 35 lbs. Thus, it's not entirely impossible that some of the space hardware over it's life, and death, can contribute more of certain unusual elements to the atmosphere than meteorites do in the same period. Organic molecules however, those are a bit more concerning, as we already know that some species can greatly affect our atmosphere!