There's no safe level of exposure to lead.
Let's put our thinking caps on.
Is there an element in the universe with atomic number 82?
Why, yes, yes, there is.
Is it present on Earth?
Surely so.
Is it going to contaminate you?
Well, maybe.
Is everyone on Earth exposed to it?
Yes, to one extent or another.
Does it affect everyone?
Some more than others, most undetectable.
Is it a good idea to drink wine with lead in it (like the Romans did)? No, not really.
How about eating lead paint chips? That good? Not so much.
Does the body naturally remove or chelate (tiny, miniscue) amounts of lead? Yes. It's thought by some that milk thistle and garlic help, but I've not studied that, and there's one hell of a lot of quack, bonkers, whacko "medicine" around in the USA. One need look no further than the current head (Ghu help us!) of HHS to see that.
So, while I agree that it's really not a good idea to be exposed to lead, exposure of some amount is unavoidable, and for the most part, in tiny amounts (how tiny? I'm not sure) it isn't causing damage we can detect. Now, Thomas Midgley, Jr., an American chemist, is credited with adding tetraethyl lead to gasoline in 1921. The amount of lead emitted into the environment was damaging, detectable, and that's why we have unleaded gasoline now.
Point being that we can't measure the effects of miniscule amounts of lead, so therefore, it could also be said that
small amounts are actually beneficial as the stress triggers our immune system
AKA as Homeopath - largely debunked and discredited. For now. I mean, they're still arguing over if eggs are good or bad. Is this because the people reaching things are stupid? No, it means as new facts are added, the conclusions change. Like the engineering professor that never changed his test questions. No need. The answers change as the state of the art progresses.