Poyturf has been in use at several tracks for a a few years and I haven't heard this issue about "dust" raised until now at Turfway. Maybe somebody screwed up when they installed it there?
In any case, I would think that some of the jockeys would have raised the issue with management or the press if thay thought something was putting them at risk.
The jockey community is pretty good at making it known when they feel that riding conditions are hazardous, and rightly so. So far, the only comments I've heard from trainers, owners, exercise riders and jocks who've actually ridden on the track, have been positive.

Bob