I grew up with and still have a lead water service supplying water to my home with no adverse effects.
What’s the science then behind these claims that lead is harming wildlife and/or children?
Is it just enviro hysteria?
According to what I’ve been able to find in the medical literature the effects can be terrible, but they’re rare and exposures must be very high and in young children for the most part.
Yes, and lead solder used in copper plumbing systems as well. This is why our parents used to tell us not to drink hot water straight from the tap. Most (but not all) chemicals are more soluble in hot water than in cold, and lead is no exception.
The lead that kids ingest is overwhelmingly from paint; when added to paint, lead compounds make the paint apply smoother and stick better. They also make it fungus-resistant. Lead in paint was banned in the early 1970s, at least in paint intended for residential use. I think they still use it on big things like bridges and the hulls of ships, but I'm not sure.
Lead was added to paint in the form of water-soluble salts, (lead chromate or lead carbonate). It was also used for quite a while as an insecticide for produce, particularly apples. It was actually used in the form of "lead arsenate," an unbelievably toxic compound of lead and arsenic. There are orchards in North Carolina (and elsewhere) that are still contaminated with this stuff.
Another huge source of lead was leaded gasoline. This had a small amount of a compound called "tetraethyl lead" added, in the ratio of 1:1260 by volume. This put a few grams of lead into the atmosphere with each gallon of gasoline burned in the nation's automobile fleet (and airplane fleet too). I believe the lead in the exhaust was in the form of finely-divided metallic lead, but I'm not sure about that. I have read, however, that there are street corners in major cities like New York City where the soil under the sidewalks contains as much lead concentration as the soil that immediately surrounds lead smelting plants near mines.
The use of lead additives in automobile fuel was banned in the seventies, as I'm sure you know.
Lead piping becomes coated with minerals in water systems so after a short time it has no real contact with water flowing through the pipes.