Traditional culture and modern day use of manos and metates 

it has to be cured before using it for the first time to avoid that issue.

I guess pick your poison. Rock dust. Micro plastics. Or metal dust. Most foods will have at least 1.

@@CarloHurtado23 yup all 3 plus bugs

I guess you can also say goodbye to brushing your teeth, perhaps even stop using any kind of ware--in fact, why not just stop eating and breathing because of the potential toxins in the air. & Metates are traditionally carved from volcanic rock, which is considered food safe. You have to SEASON/cure it and the more you use it the smoother it becomes just like your regular granite mortar and pestle.

It was a tough life for these people. While visiting pueblo areas we learned they were only expected to live to mid 40s. Sand was in most everything they ate and the teeth were worn down as a result.