Of course, that question can be turned around: if there is so much environmental decoherence, in what way can one consider that these quantum states are relevant to the "definition" of a human being ? I mean, *does it matter* to the person in question that there are these interactions with even a high vacuum ? If we make errors due to this decoherence, would the human being being teleported actually mind ? Because the original also suffers that decoherence, and seems to do all right with it.Yes, the decoherence/quantum noise does make the teleportation of a human extremely difficult. I'm guessing that putting a human in a vacuum does reduce the quantum noise to some degree, but that measure alone would probably not be nearly enough. One thing to keep in mind regarding vacuum is that even the best laboratory vacuums (pressures of around 10-12 torr) still have a particle density of around 35,000 particles per cubic centimeter. So a human in an ultrahigh vacuum still has plenty of interaction with the environment.