But recent studies suggest the level wasn't high enough to do a lot of damage.
The tests on the Tiber sediments were striking. They showed that two kinds of water mixed in the river. The first was natural river water, which carried lead isotopes originally from the Apennines and volcanic rock in the Alban hills south-east of Rome.
The second type was much cleaner drinking water, that had drained into the river, and was contaminated with isotopes of lead not found in Italy. The researchers believe the lead was mined elsewhere, perhaps in Eifel in Germany, or even the English Pennines, and then brought back in ingots to make lead piping.
Further tests on the sediments showed that levels of lead in the Roman tap water varied over time from 14 to 105 times higher than those found in natural spring water,,, Even so, Albarède believes that any health problems caused by lead piping could not have brought the civilisation to its knees.
"Can you really poison an entire civilisation with lead? I think it would take more than lead piping in Rome to do that," he said.. The findings are reported in the Proceedings of the National Academy of Sciences.