Should be "pristine" if new. Say "if new" as the post reads that you may have purchased used from someone and it is "new" to you.
Lens like these are assembled in clean rooms. Personel hooded and in a coat with air filtered. Basically at assembly nothing in the room to cause a possible problem.
Since the lens cell is almost completely sealed then usually difficult for anything to get in at all. Fine dust maybe due to warming and cooling effect of expansion and movement ofair in and out. But someting of any size it should be almost totally impossible.
So guess someone has hauled the lens cell out and maybe tried to adjust things that require freeing up the lens - thinking thoughts along "I can check/change/better the collimation if I play with this".
If it is/was a used item then unsure. Should be clean, would expect some fine dust as over time it tends to get everywhere. Still think that big bits mean someone has been making adjustments. But those lens are in a cell with retaining rings that prevent crud getting in. So someone has been sloppy.
I am fortunate here, know someone 12 miles away that will check and adjust scope lens. Sort of semi retired optics engineer and he does it for one of the retailers. Have taken an ED doublet to him for us to "play" with. I wanted it checked as I had a little bump with it.