Thats the point innit dude how much copper is there in a modern bike engine?
Its like saying that there's formaldehide in cigarette smoke which makes it dangerous, yes there is, but in such minute quantities that you get more from digesting a salad sandwich than you do from a whole pack of cigarettes. Everything is relative!
How do you prove anything is good or bad, you can only listen to Experts but some of those experts get bought by the industry to protect their sales, they have been known to be rather greedy you know!
Mankind only moves forward by spatial thinking and taking a chance. Ever seen this site?
http://mototuneusa.com/break_in_secrets.htm
Nutter or guru you decide! I find his work fascinating.