Its quite likely that you have spawned them by accident on your own in noggit. They are spawned in noggit (well, if you haven't spawned them as gobs but you would probably know about it). Problem is, that noggit can't render any particle effects, so it is solved there by the most simple way possible - particle effects are just not shown there. So, when you have object made entirely of particle emitters... You have no way how to display it in noggit. But, and thats much bigger problem, you also have no way how to target and delete them. But you can spawn and even save them in noggit.
So if those objects truly are spawned via noggit, you are basically screwed. You can:
1. Use Clear models in Assist menu - this will (well, should, it sometimes leaves one object, dunno why) delete all objects on ADT, and start with spawning again. I highly recommend keeping backups of your maps at least from time to time.
2. pick model which is spawned there (well, assuming that you know/can figure out its name and path) and you can either replace it by invisible model, or you can retexture its particle textures so they won't be displayed ingame, in both cases you can make a copy of that model (and/or textures) with different name, so you won't loose any original files
3. open ADT's structure and delete that model from there manually. I have never done anything like this but as far as I know it was somehow possible.
