Nope… No paywall on this version here dude :-

https://www.popularmechanics.com/science/math/a20718322/building-a-time-machine/

This is exactly what the research guys have concluded, whether it be dusty folks in war zones, emergency service personnel or just your ordinary, average everyday dusty dude in the street. The inflammatory response is triggered by a build up of nasties in the body, a combination of toxins, fine particulates and biological pathogens, the end result is immune dysregulation…Bingo!

And again, what you consider to be merely an economic issue is exactly where you seem to be missing the point.

Quarrying is environmentally destructive. It has contamination and pollution issues. It carries health issues. As well as the costly logistics of transporting bulk around the planet. Governments these days no longer wish any company, large or small, to go around tearing rock, in any form - pre ground or otherwise -out of the ground. So your next problem would be sourcing the base materials for your manufactured product legally.

Economically, even if you did manage to quarry,crush,sieve,grade and mix your sand for lets say £1000 a ton. What architect on the planet would specify the use of such an environmentally unfriendly and costly material and what construction company in the world would pay such a price?

Architects are already specifying more sustainable materials and construction techniques are changeing, but at present, people are still destroying the planet and killing each other for sand ! That’s the current economic situation.

Nobody is saying that without a time limit and at great expence sand can not be manufactured, but it is not even that simple.

Firstly : You would have to quarry your rock of preference before crushing, sieving, grading, and more than likely, also having to transport your specific rock grains to be mixed with other types of crushed and graded chips, depending on your sands ultimate purpose.

Secondly : It is not cheap to extract stone from the earth plus quarrying leaves very big holes in the ground! Permission from authorities to open new quarries or pits is not easily obtained in most countries.

Thirdly: Crushing is hazardous, polluting, environmentally destructive and very expensive .

The sand problem has been bubbling away on the back burner for years, hence the many and various ongoing efforts from all around the globe to recycle or create new and innovative construction materials.

Why the world is running out of sand

Our planet is covered in it. Huge deserts from the Sahara to Arizona have billowing dunes of the stuff. Beaches on coastlines around the world are lined with sand. We can even buy bags of it at our local hardware shop for a fistful of small change.

But believe it or not, the world is facing a shortage of sand. How can we possibly be running low on a substance found in virtually every country on earth and that seems essentially limitless?

The problem lies in the type of sand we are using. Desert sand is largely useless to us. The overwhelming bulk of the sand we harvest goes to make concrete, and for that purpose, desert sand grains are the wrong shape. Eroded by wind rather than water, they are too smooth and rounded to lock together to form stable concrete.

The sand we need is the more angular stuff found in the beds, banks, and floodplains of rivers, as well as in lakes and on the seashore. The demand for that material is so intense that around the world, riverbeds and beaches are being stripped bare, and farmlands and forests torn up to get at the precious grains. And in a growing number of countries, criminal gangs have moved in to the trade, spawning an often lethal black market in sand.

https://www.bbc.com/future/article/20191108-why-the-world-is-running-out-of-sand

You could be right on the governments dislike of a popular and profitable imported product!.. But what about RPE ?

RPE will not eliminate disease in cases of extended long term exposure.

RPE has only to be used as ‘The very last resort’…and is only supposed to be used as…‘The very last resort’…and only as…‘The very last resort’ for short periods of time, as…‘The very last resort’

Why do so many people equate the usage of respiratory protection with ‘A Safe Working Environment ?’

In areas where long term usage of such protection is required, an operatives working environment is exactly the opposite of ‘SAFE’ !

There is No Known Safe Working Exposure Limit when working in respirable crystalline silica dust…NONE !

Nope the link is there , just hit the thumbnail

Why no image attached… I do not know…Another of life’s little mysteries I suppose 👽👽😳