What kind of dust mask are you using? Are you sure it will block the
particle sizes created by grinding?

I use a half face resperator with 3M cartridges and prefilters.
I also use this setup when cleaning up model engine castings with
a grinding stones or cratex (using a foredom).

The rockwell toolmakers grinder is not capable of flood coolent but
does have a mist coolent system. Sound like I sould install an exhaust
fan and try it out.

cs