Q. Can sanded grout exposure cause some serious effects?

Hello doctor,

The query is about sanded grout exposure. I am quite concerned about my girlfriend’s exposure to silica dust. We were doing a home renovation. I left for about 1.5 hours while she was removing tile in a kitchen. When I had come back I saw she was removing grout with a grinder and no dust mask. The room was filled with dust in the air. The room is about 10x9 with 12” tiles. This makes for a total cut distance of 1100” with the grinder. Assuming a 1/8” cut with a depth of 3/8” and this works out to 51.56 cubic inches of dust released into the air. Assuming an average of 25 % silica content in the grout and weight of 38 g per cu inch for the dust, that is about 490 grams of silica dust releases into the air. The room was open to adjacent rooms so I estimated about 90 cubic meter space, wich would work out to 5.4 g/m^3. She was doing this for about an hour and a half so I estimate about 1 m^3 was inhaled. From what I have read this is really high-level exposure.

Is my math wrong? Did I miss something? I am making her go to the doctor and we will monitor her health closely. I am really concerned this could lead to serious problems in the near future.