[USAnum1]

Not only that, up to the late 20th century many products other than pipes contained lead. Lead paint, leaded gasoline, etc. The jury was out on lead in everyday use until quite recently.

I doubt the poisonous nature of lead was well known when these cities were built.

[maxerickson]

https://en.wikipedia.org/wiki/Lead_paint#History

[USAnum1]

Most homes built before 1960 contain heavily leaded paint[0]. My assertion isn't that lead wasn't believed to be dangerous, rather that no one saw it as "seriously" dangerous.

https://en.m.wikipedia.org/wiki/Lead-based_paint_in_the_Unit...

[roywiggins]

From the above wikipedia entry:

> In the July 1904 edition of its monthly publication, Sherwin-Williams reported the dangers of paint containing lead, noting that a French expert had deemed lead paint "poisonous in a large degree, both for the workmen and for the inhabitants of a house painted with lead colors."

"Poisonous in a large degree" seems pretty serious to me.

People were regularly dropping dead due to lead poisoning in factories by the turn of the century, and it looks like lead was recognized as being capable of doing significant, though hard-to-recognize, harm:

"Although plumbism is usually easy to diagnose, lead occasionally induces obscure affections of the nervous system, the cause and true nature of which are not always easily recognized. As a cause of poverty, too, its influence is not sufficiently known nor the role it may be playing in the physical degeneracy of the race."

https://books.google.com/books?id=gQY9AAAAYAAJ&lpg=PA29&ots=...

Lead paint looks to have been largely banned in Europe in favor of zinc-based paint by 1911; it was clearly viewed as a public health threat, not least by housepainters themselves, who were dying of lead poisoning (see the table on page 25).