Too smart by 1/2.
I am not sure if the vacuum is blowing or sucking. If it's sucking, it's sucking the dust into the hood. If it's blowing, it's filling the hood with air that very likely contains all kinds of unhealthy organisms.
What is ridiculous here is, apparently the dust only bothers him when it comes directly out of the sand blaster. The rest of the time, he seems to be okay with breathing it.
I see people make the same mistake with paint.