Everyone has a theory on the best way to learn about a person. It’s how they treat the server at a restaurant, or how they act when they’re drunk. But according to MIT engineer Carlo Ratti, you can tell the most about someone by sampling their microbiome, and “the sewage system is the great aggregator.” Gross, sure, but Ratti is studying waste to understand everything from heroin use to antibiotic-resistant bacteria—and all with the help of a sewer-slurping robot named Luigi.

MIT Senseable City Lab

The potential is obvious: If there’s an outbreak of the flu virus, the pipes will be the first to know. But waste also carries drug metabolites, DNA, even biomarkers for diabetes—and all that data is available in real time. That’s the aim of the MIT-sponsored Underworlds project, which began with a pilot program in Cambridge, Massachusetts. Of course, there’s the problem of, uh, collection. “It’s dangerous to be leaning over a manhole holding a 20-foot sampling pole,” says Mariana Matus, a researcher on the project. “And then you have a bottle that’s dripping with sewage.” Enter Luigi, which is remote controlled and easy to decontaminate—the first step toward a fleet of self-directed gadgets that the Underworlds team envisions in a smart sewer system.

And with Underworlds preparing to expand to greater Boston and Kuwait City later this year, the promise is huge. “Often, data from the people with the most problems isn’t recorded, because they don’t go to the doctor,” Matus says. Now public health can be priority number one—thanks to plentiful number two.