Last Halloween, the FDA said that some cinnamon, a spice loved by many kids and adults, was contaminated with lead, a metal that can cause irreversible damage in babies and young children.

Virtuosic pianist and composer Beethoven suffered from several debilitating ailments. A new study suggests lead poisoning may be at least partly to blame.

Ten years ago, Flint, Mich. switched water sources to the Flint River. The lack of corrosion control in the pipes caused lead to leach into the water supply of tens of thousands of residents. Pediatrician Mona Hanna-Attisha recognized a public health crisis in the making and gathered data proving the negative health impact on Flint's young children. In doing so, she and community organizers in Flint sparked a national conversation about lead in the U.S. water system that persists today.

Today on the show, host Emily Kwong and science correspondent Pien Huang talk about the state of Flint and other cities with lead pipes. Efforts to replace these pipes hinge on proposed changes to the EPA's Lead and Copper Rule.

Have questions or comments for us to consider for a future episode? Email us at shortwave@npr.org — we'd love to hear from you!

The Windy City has the most lead pipes of any U.S. city. A study estimates that more than two-thirds of children there are exposed to lead in their home tap water.