Explanation: The Romans used lead-lined cookware not in ignorance of its dangers, but wholly cognizant of them - the Romans recognized lead poisoning from various sources, and regarded lead as 'unwholesome' to human health.
They used lead widely in many applications that they could be forgiven for thinking were not dangerous - they understood how to prevent lead leaching in pipes, and used lead in writing tablets. Less forgivably, in cosmetics. But most dangerous of all was the use of lead pots in making 'defrutum' - sweet grape syrup, which wealthy Romans loved to put on everything. The thing is, the process uses lead specifically because other materials won't do - copper and iron leave an aftertaste, while lead vessels actually make it sweeter, as lead acetate is slightly sweet.
What's a little harmless poison in your condiments, after all?