Is there... a word... for... 'exposed to the void of space for a prolonged period of time'?

Yeah I know fossilized isn't the right word, as thats generally a process that requires water... but i dont know how to say 'space fossilized'.

Dehydrated and Irradiated ... ?

I think the poop bags were mainly stowed into lockers on the sides of the descent module. They're not just piled up on the ground.

Edit: Correction. This research suggests that the procedure was to "jettison" the "waste receptacle," containing any sealed poop bags, food wrappers, and other trash. "Jettison" definitely sounds more like tossing stuff out the door.

I also want to point out that maybe 96 bags were provisioned and left. But almost certainly most of those remained empty. Pooping into a bag in the LM in close proximity to your colleague is not an easy or pleasant experience. Astronauts had access to lomotil and they were conditioned on what NASA called a "low residue diet" for the entire duration of the flight and pre-flight quarantine. The early flights were on the surface for less than 24 hours. So there was a lot of opportunity and incentive to just avoid having a bowel movement on the moon.

There's also a radio transcript from Apollo 16 that suggests that, on that flight, this material was transferred off the returning LM back onto CM and presumably returned to Earth.