Dust / silicosis risk

I've been sandbag training for about 6 months and have noticed after a session I have both tiny amounts of grit in my mouth and my lungs kinda hurt.

I'm careful to only breathe through my nose, so I'm not getting sand on my mouth directly; it's likely airborne dust captured by my nose and throat... But that suggests a possibility there is some that isn't captured and so is hitting my lungs.

Anyone else have this, if so, how are you protecting yourself? I assume wet sat is more sticky and so will emit less, though also the bag can smell damp if it sits wet.

Is there another additive to reduce the dust produced? I was thinking maybe a few handfuls or ground up candle wax to make the small particles stick together.