Interesting research 

 

https://blog.mann-hummel.com/en/new-idea-dusty-problem/

There is gold in them there gutters, or at least platinum and other precious minerals and there are now actually companies experimenting on processing

the dust / dirt gathered at road sides.

News articles on it and videos for a number of years but it has been given little real publicity to date.

Iirc it got a thread mention here at one stage?

Could well have done. California legislation sets specific requirements for friction material compounds, primarily to avoid contamination of ground water. 

On 25/09/2017 at 20:20, Headinawayoffski said:

There is gold in them there gutters, or at least platinum and other precious minerals and there are now actually companies experimenting on processing

the dust / dirt gathered at road sides.

 

There's more in the sewers.

Every time someone wearing rings washes their hands, precious metal particlulates get washed down the drain. Based on sampling done, we estimated several million Pounds worth gets washed down every year.