While most people wouldn’t be too excited about anything that came out of a sewer, Phillip Barbeau, a professor of physics at Duke University, tells me enthusiastically about 3 tons of lead that was recently pulled from Boston’s waste system. The metal, once used to seal pipes, is one of his more promising potential sources of “low-background” lead for his experiments. It’s now sitting at Los Alamos National Laboratory, the birthplace of the atomic bomb.

Low-background metals — most famously steel and lead — are valuable because they carry particularly low levels of radiation compared with most conventional materials. Used as shielding in advanced particle physics projects and for medical science devices like X-ray chambers, these metals won’t interfere with specialized, highly radiation-sensitive environments and tools.