All it takes is a change in ph of your water supply to put you at risk.
(ETA: It also caused lead to be released- non-lead pipes had actually leached lead from the water over many years, acting as a filter. The lead was chemically bound to both lead and non-lead pipes. Changing the chemistry caused the process to reverse and dump all that lead back into the water at much higher concentrations than would occur just using a 100% lead pipe system.)
And lead paint is similar. In-situ it's pretty harmless. It's the removal that's dangerous and is more likely to poison.
This is why people arguing for "do-something!" actions using "What harm could it do?" reasoning should always be fought until safety is confirmed experimentally the field.
"What harm could it do?" should always be a red flag for "don't know what you don't know" ignorance, and responded to as if it's a real, non-rhetorical question.
This is not completely true. I remember some studies looking at lead accumulation in dust. It's not just macroscopic paint chips on the outside of houses that children ingest, it's dust in the house as well.
Just replacing the pipes seems like the optimal solution, but half-measures are better than nothing.
In London or the general area? The water is lousy with calcium, hard AF, so that's a good bet.
The notorious lead in the water issue in Flint, Michigan was not just "pipes made from lead" but also that they carelessly switched water supply to a new one that over time, corroded the deposits off the inside of the pipes so that the lead could leach out.
Once that had happened, "the damage already done to Flint’s water supply infrastructure by more than 18 months of exposure to corrosive water. Even after the water supply was reconnected to the (original water supply), officials advised against drinking Flint water."
https://www.britannica.com/event/Flint-water-crisis
As to what to do with your pipes - you can find water testing kits on the big online retailer for under £30
Where was the water tested? I've heard that here in France, water is often tested before going into the pipes, and not after flowing for the faucet. If that's the case for you too, I'd encourage you to test the water going out of the faucet, since this is the water you actually drink. In France we can do that at labs that take care of stuff like blood samples. A naive search gave me this website https://watersafetestkits.co.uk/which-water-test-kit/ that sells water test kits, for example.
I'm not going to look up those chemicals - I doubt that they would pass modern safety standards. If you maintain a water supply that has lead anywhere you should figure out what modern chemicals to use to prevent lead (or whatever your pipes are made of) from being eroded. I hope the people who maintain water supplies already know about this though.
Our water was tested years ago by the waterboard and came back way below the legal limit.
Yet still... I'm suspicious. Can anyone point me at resources to help prove it's unsafe?