I grow Organic all of my outdoor plants/gardens and I was a terrible Organic snob many years ago, but once I became aware of the heavy metal content of so many organic amendments I switched to clean mineral salts indoors. You can grow low heavy metal crops organically, but it isn't easy, since some of the most popular organic/living soil amendments are very high in heavy metals, such as rock dust, lobster/crab meal, kelp, rock phosphate, diatomaceous earth, worm castings (I hate that this is true, love me some castings-also, this is due to the rock dust that is commonly fed to the worms), insect frass, among many many others. This stuff all adds up and accumulates. Back when I really cared about organics, I was mostly worried about synthetic pesticides and herbicides-heavy metals didn't even factor in for me. I actually just assumed that organics would be lower in heavy metals-which can be the case if compared to older, heavily polluted mineral salts. But now we have complete mineral salt formulas that test out "below detectable levels" for the common awful heavy metals-arsenic, cadmium, and lead.
I know I do tend to go on and on about this topic, but I think people should make informed choices based on real world facts, and not just what we want to be true. I would encourage all organic growers to look up every single product/amendment they use in one of the state heavy metal databases (Ca, OR, WA all have good ones), especially if they are making a no-till soil they plan on reusing for years. I made up a batch of excellent organic soil last year with everything in it testing BDL for heavy metals, but it wasn't easy or cheap, so for now I'm sticking with coco/clean salts and zero synthetic pesticides/herbicides. One example of a good organic substitution is, if you want to use crustacean meal, typically crab/lobster meal, use shrimp meal instead-since shrimp eat lower on the food chain, the meal lacks the heavy metals that larger crustaceans accumulate (but still check your product in the databases.....https://apps1.cdfa.ca.gov/fertilizerproducts/ or
https://agr.wa.gov/departments/pesticides-and-fertilizers/fertilizers/product-database or
http://oda.state.or.us/dbs/heavy_metal/search.lasso