Important health note- silica sand cuts extremely well- it is also deadly. The freshly shattered grains of sand are especially nasty. Produces a condition called silicosis when you inhale enough.
Fatal, no treatment, no cure, and a really crappy way to die. Watched dad go that way- too many years of running a rock drill, no respiratory protection.
2 means of dealing with it- first, do not breathe the air with silica. A well sealed cabinet will contain- but WAIT a few minutes for the airborne stuff to settle before opening cabinet to remove work. Open air sandblasters wear a hood with an airline pumping clean air into the hood.
Second, use something other than silica sand. Black Beauty (coal slag) has no silica, works like sand. There are also soda blasters that use baking soda as the blast medium.
What we have heah is.... failure to communicate.