I'm hoping that the more 'rugged' build of these devices prevents that issue. I work in an area where the phone would be exposed to metal dust.
Not in an area where the air is filled with metallic dust. (One of my jobs as a tech, years ago, was removing iron filings from the speakers of walkie talkies that were being used in high iron construction. A filter that will keep that dust out will keep sound in.)
About the only thing I've ever found that will protect a phone from metallic dust (and that's if it's not molecular size particles) is a pair of plastic zip baggies. Put the phone into one and zip it closed. Put that one, zipper first, into the second one and zip it closed. You can still hear through that plastic.
Metal particles short electronics, so you can't make a jack with a hole in it (and there has to be one, to plug the earphone plug into) that's immune to metallic dust. And, as the dust moves around inside the jack, it shorts and unshorts, causing crackling. Air movement does it, the natural muscular action of your hand, even if you're holding it still, does it, even clamping the phone onto a seismograph table will cause it if the particles are small enough. Nothing is infinitely stable. Even the Brownian motion of air molecules, if the metallic particles are small enough, will cause crackling. And cellphones don't work so well in absolute vacuum.