The Anatomy of a Taco

We have come to expect that most of the packaged food found in grocery stores arrives from thousands of miles away. But what about the taco from the food truck down the street? Students at the California College of the Arts URBANlab program took on the surprisingly difficult task of tracking the ingredients from a taco purchased at Juan's Taco Truck in San Francisco's Mission District.

The unsettling results: a single taco contained ingredients that traveled 64,000 miles. Some of the...