@thor It's likely of no consequence. Heavy metals are naturally occurring and we are likely exposed to some of them. If drugs like stimulants cause damage, does damage accurately describe the obliteration caused by the less horrifying of the oxidizers?
I just hear a propaganda machine trying to cause fear and control the public. The US tried that and they still do it. People buy into it and the government destroys more lives in their crusades against drugs than drugs ever could. They pay researchers to find evidence that supports their conclusions.