If dust particles are large enough, and numerous, things can get pretty awful.
With discs in spindles, this has actually given me trouble more often than I would like to!
Actually I think it's possible that many users are not aware of this problem, so I'll post an "extreme" example just to get people scared enough so they will pay attention... nyark nyark... LOL
TYG02 (Verbatim DatalifePlus 25-discs spindles from 2005/09)
Both burns with NEC3540A 1.W5
1. First disc of the spindle: lots of dust (straight from the spindle, no check before burning)
Lots of dark spots are visible after the burn, just under each speck of dust.
2. Second disc of the spindle, clean (wiped with antistatic before burning)
Visually perfect surface after the burn.
As I stated before, this is probably the most extreme example of this dust issue. But who knows?