I have been a regular smoker of marijuana for about five decades. I have to get blood work done routinely and have never had any indication of lead or other metals. Maybe your results were contaminated by something in the lab...or you have allowed a preconceived idea to push an agenda. I can't say why you're trying to put a bad name on a good product that helps people all over the world deal with pain, anxiety and depression. Do more research, use the scientific method and apply Occam's Razor before deciding you have every answer. Please.