Peter I think you have a serious misunderstanding about "chemical" and "organic" compounds. Heavy metals and urea can be found in both organic and inorganic fertilizers. You can easily purchase nitrate nitrogen based fertilizers that have no urea or heavy metals. A guaranteed analysis and strict government regulations on fertilizers makes it easy to lookup online. Avoid the heavy metals and urea. Its not hard in 2015 to do this. Its a different story with bottled juices like advanced nutrients. They are sold as a supplement in many places to avoid the government regulations on fertilizers.
As far as there being "chemicals" in the leaves. Im not sure what chemicals your talking about. Organically grown cannabis is up taking the exact same chemical elements as the inorganically grown. Nutrients are just chemical elements. Water is a CHEMICAL COMPOUND. Nobody says a plant is grown chemically if you give it water. Yet water IS A CHEMICAL COMPOUND. Plants need basic chemical elements (Nitrogen, phosphorus, potassium, etc...) to create more complex molecules. Such as chlorophyll and later cannabinoids and terpenes.
Whats food for plants isnt always food for humans. If you take a cup full of the organic soil, which could contain bat guano, fish emulsion, bone meal, billions of bacteria, and you eat that then your going to have a problem. You cant eat that stuff. Its toxic to humans.
Im new here and I can't tell if your trolling or if your serious.