when was it discovered that lead was poisonous
Lead poisoning In 2013 lead is believed to have resulted in 853,000 deaths.[2] It occurs most commonly in the developing world.[2] Those who are poor are at greater risk.[2] Lead is believed to result in 0.6% of the world's disease burden.[5] People have been mining and using lead for thousands of years.[4] Descriptions of lead poisoning date to at least 2000 BC,[4] while efforts to limit lead's use date back to at least the 1500s.[5] Concerns for low levels of exposure begin in the 1970s with there being no safe threshold for lead exposure.[2][4]
Plumbing Present-day water-supply systems use a network of high-pressure pumps, and pipes in buildings are now made of copper,[25] brass, plastic (particularly cross-linked polyethylene called PEX, which is estimated to be used in 60% of single-family homes[26]), or other nontoxic material. Due to its toxicity, most cities moved away from lead water-supply piping by the 1920s in the United States,[27] although lead pipes were approved by national plumbing codes into the 1980s,[28] and lead was used in plumbing solder for drinking water until it was banned in 1986.[27] Drain and vent lines are made of plastic, steel, cast-iron, or lead.[29][30]