I am almost 100% sure there are no significant pollutants in my soil - not because I don't add them, but because nothing stays in this soil - it's almost pure sand, Dice - everything added disappears with the first rain. My worry is groundwater, which, of course, I share with all my neighbors for several miles around.
And that, interestingly enough, is exactly why I have nematodes - no organic matter (not that I haven't tried!!). One would think the nematodes would wash down with everything else, but they must have some way of clinging to the grains of sand.
The sand, actually, is not a bad growing medium (if it weren't for the nems) - if you're into hydroponics that is, because that's about what it amounts to here. "Sterile" medium (I wish!), all nutrients added.
The thread has come full circle back to the topic! That's unusual.
Jack