The evidence shows that silica is very dangerous in these environments and occupations, and one could surmise that it is dangerous elsewhere. I conclude that the reason I cannot find information on the dangers of crystalline silica on road surfaces, or laws protecting me and you, against such actions , is because it was never believed that anyone would be stupid enough to take quartz and granite mine tailings, silica dust, and use it as road surface material. Well, believe it, that is what the Nova Scotia Department of Transportation and Public Works has done. Clay soils can be used to make pottery or bricks, sandy soil or sand can be used to make glass. Basically silica is crushed glass .
Lungs take care of normal dust.
Fortunately, the body's respiratory system does a good of job filtering out dust and most foreign bodies. Fine particulates such as asbestos and silica, however, are so tiny they can get past our filtering system. This may cause serious lung problems over an extended period of time if protection or controls are not used. Respect these tiny invaders. Use the appropriate personal protective equipment and safety precautions.