As a general rule; Dust does not belong in our lungs.
Our bodies have quite advanced defence systems to prevent foreign particles from entering and remaining in our respiratory systems. Coughing reflex, mucous membranes, and the chemical components of our immune systems all help keep our lungs healthy and functioning. We do however; in some environments need external assistance, particularly in the workplace. Dust produced or encountered in an occupational setting should be eliminated or exposure reduced, as far as reasonably practicable. OHS & WHS legislation, regulations and guidance material places legal responsibilities upon employers to keep employees from being exposed to substances above specific exposure standards.
No dust is good for us, but there is an abundance of scientific evidence purporting that some are much more hazardous than others; asbestos dust is well documented, silica, to a lesser extent.
Respirable crystalline silica (a-quartz) is a natural and abundant mineral present in many types of rocks and soils on Earth. It can be found in various concentrations in products such as bricks, asphalt, concrete, sand, crushed rock, cement, plaster, soil, stone etc., and silica dust is easily generated when such products are disturbed by any means. Silica's physical properties allow it to penetrate deep into lung tissue, bypassing our bodies natural defence systems, and causing scar tissue to form, leading to very serious illnesses such as silicosis. Silica is invisible and does not produce short-term symptoms, much like asbestos. This tends to mean that it is often 'out of sight, out of mind', meaning people forget how important it is to consider silica risks in their own workplaces.
Emphasis must be on limiting exposure, ideally utilising the hierarchy of controls. Eliminate first, PPE last.
Some applicable recommendations include but are not limited to:
Some helpful guidance material can be found on the WorkSafe Victoria or SafeWork Australia websites.