I was gonna go with "Australia is not an island" but, well, I think we can see the problem in that statement. :-)
In the United States, OSHA (Occupational Safety and Health Administration) has implemented strict guidelines regarding silica (https://www.osha.gov/sites/default/files/2018-12/fy16_sh-296...). Silica is highly present in things like concrete, so it is weird to me that something other than concrete would be singled out.
> You appear to have made a quip unsupported by medical data.
No, I have not. The "quip" is ignoring the other sources of silica while singling out this one particular one.