Earlier quoted context omitted.
To be fair lead pipes aren't good, but the other uses in the Roman Empire were probably the cause of far more of the issues. Especially with hard water (of which the water in Rome is VERY hard[1] today, and if similar sources are used, it stands to reason it was very hard way back when) it forms a scale that drastically reduces the amount that leeches into the water. [1] https://www.researchgate.net/figure/Map-of-wat…
That is exactly what people told him at the time: https://news.ycombinator.com/item?id=43231697 He is being dishonest.
> It is now universally accepted that utilization of lead for domestic purposes and water distribution presents a major health hazard. The ancient Roman world was unaware of these risks. How far the gigantic network of lead pipes used in ancient Rome compromised public health in the city is unknown...[Lead isotopes in sediments from the harbor of Imperial Rome] demonstrate that the lead pipes of the water distribution system increased [lead] contents in drinking water of the capital city by up to two orders of magnitude over the natural background. The [lead] isotope record shows that the discontinuities in the pollution of the Tiber by lead are intimately entwined with the major issues affecting Late Antique Rome and its water distribution system.