In some ways, the ancient Roman city of Pompeii mimicked a modern city — once contained within protective city walls, as the urban area grew and prospered, it spread into the countryside, creating suburbs. But in other ways, it was extremely different. Pompeiians had a relationship to their garbage that sounds like the polar opposite of ours.

Archeologists say it's important to remember that all societies — past or present — don't have the same attitudes towards cleanliness or sanitation. What constitutes garbage, and how and where to keep it is decided by community members. Think about it: litter is a malleable concept, and even in the modern era it used to be acceptable to leave trash behind. Many smokers still think it's OK to toss their cigarette butts out the car window.

Understanding how different cultures see death and garbage is one key to understanding them. In Pompeii, tombs were put in high-traffic parts of the city (to better remember the dead) and disposal pits were kept in the same spaces as water storage. They also sorted their recycling differently. Instead of packing it up and sending it to a faraway state (or country, like the United States used to do with China until they started refusing it), new evidence shows Pompeiians recycled right at home.

Archaeologists figured this out by examining piles of detritus and the types of soil it contained. Human excrement or household food waste would leave behind organic soils in a pit, and street litter would pile against walls and get mixed in with the area's sandy soil, degrading into similar soil, not the darker, richer organic stuff. Some of that litter would be found in sizable piles, bigger than what would have been swept or blown aside by busy foot traffic.

"The difference in soil allows us to see whether the garbage had been generated in the place where it was found, or gathered from elsewhere to be reused and recycled," Allison Emmerson, an archaeologist at Tulane University who was part of the team that conducted the dig, told The Guardian. (Further detail of Emmerson's research is set for an upcoming book, "Life and Death in the Roman Suburb.")

https://www.youtube.com/watch?v=9G6ysTKQV68

As the researchers delved into 6-foot-high piles pushed against the city walls, they found materials like plaster and broken ceramic bits. Originally, these piles were thought to be part of the mess left behind when an earthquake ravaged the city 17 years before Mount Vesuvius erupted, but it's more likely to be evidence of recycling, posits Emmerson, since the archeologists found that same type of material was used as building material elsewhere in the city, and in the suburban areas. (Skip to 15:30 in the video above of a recent lecture by Emmerson to see what a Pompeiian street looks like today and explore the businesses and city plan.)

The archaeologists already knew that the interior walls of Pompeii's buildings would often contain pieces of broken tiles, chunks of used plaster, and pieces of household ceramics, which would be covered over with a top layer of new plaster for a finished look.

Now it was obvious where that interior wall material came from — the carefully sorted "recycling bins" leaning up against the ancient city walls. It makes sense — this was a location to dump material from a tear-down or remodel, and a place where builders could then pick up material to reuse. "The piles outside the walls weren't material that's been dumped to get rid of it. They're outside the walls being collected and sorted to be resold inside the walls," Emmerson said.

In this way, the Pompeiians weren't just recycling, they were recycling locally — with building and refuse materials removed from one area of the city and used to build in another.

Considering that construction waste is at least a third — and maybe as much as 40% — of landfill space, this is a lesson modern societies could take from the ancients.

Emmerson explains why: "The countries that most effectively manage their waste have applied a version of the ancient model, prioritising commodification rather than simple removal."

Starre Vartan ( @ecochickie ) covers conscious consumption, health and science as she travels the world exploring new cultures and ideas.

Archaeologists discover recycling system in ancient Pompeii
The attitudes of Pompeiians towards death and waste was very different from our own.