We’ve talked about the dangers of silicon carbide fibers emitted by abrasive blades during cutting. There’s another source of breathable silica, though, and you can generate it no matter what kind of blade you use. This silica is generated by what you cut.
According to the Centers for Disease Control and Prevention (CDC), you can generate respirable crystalline silica (RCS), another kind of breathable silica, by cutting materials with high concentrations of crystalline silica, including brick, concrete slabs, block and pavers. The bad news is that RCS can cause silicosis, an irreversible lung condition that can lead to death, as well as lung cancer. (See this Occupational Safety and Health Administration leaflet (PDF) for more information) The good news is that you can lessen your RCS exposure.
The best way to lower your exposure is to wear a respirator or mask while cutting. If you can’t, then the CDC recommends that you attach a wet-cutting kit or vacuum attachment to your saw while cutting high-silica materials. This CDC link includes video of how these two accessories can dramatically lower your RCS exposure and increase your worksite health.
Centers for Disease Control and Prevention, “Engineering Controls for Silica in Construction“