Did you at least try them?Concrete facts...they making saxes and mouthpieces out of concrete?
Then it's just scaremongering.The message Sirvalorsax is trying to pass is more a message of caution rather than anything else.
Caution that is not really backed up by solid information. He actually says it himself: he is not presenting concrete facts.
Brass readily oxidises (aka tarnishes), and it's this thin layer that limits how much lead is available.It's true that brass can contain lead, but I've read (can't find it now) that concerns over "leeching" are not so justified in that the lead molecules would lie under the exterior coating. I'm not a scientist or metallurgist so I'll leave it there as a bit of hearsay to be corrected if appropriate.
However there is no strict control over the laed in brass, it was there originally to make it easier to machine. So most brass is probably unleaded, if you want lead in it I'm sure you'd be paying extra (1) for the more expensive metal itself and (2) for the less readily avaliable and stocked alloy.
So why would "the Chinese" use that for mouthpieces? Surely not to further their reputation as purveyors of toxic products.
Faucets! Faucets!This whole lead thing omitts the fact that if you have inexpensive faucets or older faucets in your home the brass can easily contain up to 20 percent lead. 4 percent is pretty dang low. I chose not to worry about it. Threats elsewhere are so much higher....like the epa that is allowing more rather than less raw sewage into waterways as well as clearly toxic chemicals.
Life is terminal, I recall my grandfather telling me "Sooner or later something is gonna get you".