if none of it got wet at all just exposed to humid conditions..I don't think just the humidity should have damaged them....as long as the drywall stayed dry...Consult with your supplier on what he suggest. My guess is that they are perfectly still useable. see what they suggest...may just require leaving out side or inside a day or two to let dehumidify!! If they are not wet ...cant see why they are should be trashed...others may have more experience with this same problem.