Strange, here in North Florida we sit on phosphate deposits. The area around my house was mined in the early 20th century, but I'm forbidden to use detergents with phosphate (which would go right back into the ground), because someone in DC decided it was bad. I guess everyone in my area lives on phosphate polluted land, and are in danger. We swim and fish in lime rock pits.
From what I remember the Dead Sea in Israel is full of the chemicals that can be used for fertilizer.
I think the whole thesis, on its face, is ludicrous. Phosphates are heavy molecules, they’re never going to float out of the atmosphere. All we can do is move them around, and maybe break them down into their component parts or combine them with other elements into new molecules. The elements making up those phosphates are never going to be used up, because they can never escape this planet.
If we start running low on the easily available natural sources, we’ll just have to be more careful about reclaiming and recycling them. No big deal.
Home Depot Paint Aisle - Trisodium Phosphate. Comes in a box (watch out and don’t get the ‘substitute’ in a plastic tub).
One $8 box lasts a year, a tablespoon at a time in my dishwasher.
Can be used in the laundry too.
I get mine at GFS Marketplace in Clearwater.