Lead is a heavy metal, with the chemical symbol of Pb. Lead rose in popularity due to its attributes such as high density, high malleability and low cost. It was used in the production of many consumer products like paint, plumbing materials and ammunition until lead was found to be harmful to human health if ingested or inhaled. Lead is a toxin that accumulates in the body over time and can cause severe damage to the brain, kidneys and nervous system.
Image source: U.S. EPA - Lead in Drinking Water Infographic