Not a surprise, I hope. I've been using an antifungal shampoo after clinic days for years, and the urge to put a toothbrush up my nose has been quite strong at times. All this stems from airbourne bits of bacteria and spores in treatment rooms. I've used all sorts of high tech sub-micron filters but none so far have lasted all that well and the good cheaper ones seem to have gone off the market in Aus. I'm about to get a powerful extraction fan put in one window(to change the air in the room frequently) and to buy another version of filter/catcher to use to try to capture the muck during the grinding process, this one is about $1100 and filters at 0.3 micron and doubles as a good vaccuum cleaner as well.
regards Phill Carter