You can analyse crystalline silica respirable dust on a 37 mm 10 micron filter by sampling.

20 µg/m3

1. Any hazard, but noble gases are not respirable.

2. Radon is very radioactive and dangerous.

Yes. Concrete contains respirable crystalline silica that is in the fine grey powder that hangs in the air and coats everything in a concrete construction Since crystalline silica in the form of quartz is a major component of concrete, airborne respirable quartz dust may be produced during construction work involving the alteration of concrete, thereby producing a silicosis hazard for exposed workers.

Marvin W Nichols has written:

'Respirable dust sampling requirements' -- subject(s): Coal mines and mining, Dust control