People keep saying that copper is “toxic”. Take a look at any packet of vitamin and mineral supplements and they contain copper along with iron, magnesium and other essential metals.
Copper has very fundamental part in the metabolism within the cells that allows your body to function. Iron is a cornerstone of the bloods ability to transport oxygen to your cells as part of your metabolism.
The body, if functioning correctly, takes in vitamins and minerals as part of your diet. You absorb these and your body regulates how much you take in. Excess are excreted in your urine or via the bile in your poo.
Both copper and iron can be toxic if consumed in excess quantities over time. And your bodies natural regulatory system can go wrong and have higher levels than desirable. The is in particular a troublesome hereditary condition of too much iron in your system, which can be managed. Higher than normal feretin levels are also a symptom of infectious disease in particular COVID.
Lead on the other hand has no positive beneficial effects on the metabolism of any plant or animal - or least science has yet to find any positive effects. We have yet to see the lead supporting community carry out any research showing any positive effects of lead on body metabolism.