Not dust, just macro-scale but small bits of crap.

I think some of it in my bag is from a black sand beach. That stuff kills headphones as well as wonkifying magsafe sockets.

I took a bag to the beach, then put my laptop in that bag a few weeks later. The leftover sand (because sand is basically glitter) had some magnetic bits, which clogged the magsafe connector. I had to spent like 20 minutes with a toothpick to get enough out to charge, and it was never quite back to normal.