Streets across the world are littered with gum, and although many cities have tried and failed to eradicate these sticky circles, Mexico City continues to wage this seemingly unwinnable war

Each night dozens of trucks carrying 15 people depart from Mexico City’s downtown to Francisco I Madero Avenue, the most famous pedestrian street in the capital. Armed with 90C vapour guns called Terminators, the group begins the laborious task of combing the street looking for small, black circles fastened to the ground.



It takes them three days, working in eight-hour shifts, to go through the 9,000 sq metre avenue. By the end, they have removed a total of 11,000 pieces of chewing gum.

There’s a sense of resignation among the workers. Many are single mothers who commute an hour and a half from the city’s outskirts to perform this tedious work until 5am. “It gets boring,” says one of the most experienced.

The war on gum is waged in cities worldwide. The Wall Street Journal denounced gum as a “black plague” on New York City almost a decade ago, and cities from Seattle to Singapore have made eradicating it a central part of their urban philosophy.

Facebook Twitter Pinterest The gum cleaners of Mexico City work overnight to remove thousands of chewing gum pieces from the pavement. Photograph: Alan Grabinksy/The Guardian

Yet Mexico City is making a particular stand by launching a campaign next month to raise awareness of what it deems the social and environmental costs of discarded gum. Not only do a reported 40,000 kinds of bacteria exist in Madero’s street gum, including E coli, Proteus and salmonella, but birds also eat the discarded plastic and choke, says Rosa Isela Martinez, the campaign manager.

Cleaning the sticky stuff remains a sisyphean task. One million people visit downtown Mexico City every day, and more than quarter of those pass by Madero – roughly equivalent to the daily traffic through Times Square. Alberto, a 33-year-old man with paralysis who sells gum on the street, says he sells about 60 packets a day.

Gum removal in Mexico City used to be a “type of slavery”, says Jesús Porfirio González Shmal, director of the city’s downtown authority. “The cleaning staff had to literally get down on their knees and pick each gum off using a spatula and gasoline.”

In recent years the technology available worldwide has improved and penalties have become stricter – the Statue of Liberty employs gum-cleaning staff who use specially designed GumBuster machines, and in the UK a man had to pay £845 in 2014 after refusing to honour a £50 fine for spitting out his gum.

Facebook Twitter Pinterest The chewing gum on Seattle’s ‘gum wall’ took 130 hours to remove. Photograph: Ted S. Warren/AP

But like rubbish, gum has a tendency to attract more of itself. In 2002, Bournemouth borough council began setting up sticky boards featuring the faces of Jeffrey Archer, Tony Blair and George Bush, to encourage chewers to deposit their gum there, but the habit of throwing it exactly where it isn’t wanted proved too hard to break. In 2015, Seattle cleaned up a 20-year-old “gum wall” that had become a local landmark. The job took workers an estimated 130 hours to fill 94 buckets with 2,350lb of gum, but the respite didn’t last long: according to the Seattle Times, a flash mob began to “re-gum” the wall two days later.

The cleaning staff had to literally get down on their knees and pick each piece off using a spatula and gasoline Jesus Porfirio González Shmal

Singapore famously banned chewing gum entirely in 1992. Considered an anti-utopian enemy of progress by the political leader Lee Kuan Yew, gum could get you a $500 fine or worse. (In 2004, as part of the US-Singapore Free Trade Agreement, the ban was moderately relaxed, allowing for pharmacists and dentists to sell “therapeutic” gum to customers with a medical prescription.)

But perhaps Mexico City’s authorities feel more responsible for eradicating the product because this is where habit started – at least in its modern, mass-produced sense.

Chewing gum itself is ancient: 10 years ago, a group of archaeologists in western Finland found the world’s oldest chewing gum, a 5-6,000-year-old Stone Age birch bark tar with teeth marks on it.

The term “to masticate” comes from the Greeks, who, instead of gum, used a resin made from the mastic tree to exercise their jaws. The Mayans and Aztecs drew the sap out of sapodilla trees, drying it until it became a latex called tzicli (now “chicle”). In Aztec cities, chewing tzicli in public identified a married or widowed woman as a prostitute and a man as a homosexual, according to Louis Werner, author of Unwrapping the History of Chewing Gum.

Facebook Twitter Pinterest Preparing chicle lumps after boiling them in Mexico, 1931. Photograph: Ullstein Bild via Getty Images

It was the Mexican general Santa Anna who brought chicle to American cities in the 19th century. While imprisoned in the US, Santa Anna chewed chicle to calm his nerves. He took it with him during his exile in New York, and chewed it with inventor Thomas Adams. Adams experimented with trying to use it to make rubber from car tires – but eventually gave up and mixed the product with hot water instead, turning it into little balls and selling it as chewing gum.

The habit exploded. In industrialising metropolises, chewing was seen as a form of rebellion, especially among women. In 1912, the New York Times ran a two-page piece on college girls who chewed gum and drank, “de-feminising themselves, lowering themselves”. Cleaning was a problem as early as 1936: one angry shopkeeper calculated that 84,000 pieces of gum were spat out on 25 blocks of Fifth Avenue each day.

Chewing gum became a truly global phenomenon during the second world war when it was included in American GI rations (according to studies, it was therapeutic and increased concentration). After the war, the original tzicle gave way to a polyvinyl acetate – a synthetic plastic that takes up to five years to decompose, and dries into a hard residue that is difficult to remove.

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The result has been city pavements covered in a constellation of gum marks – and the sense of an unwinnable war. Although leading gum producers including Wrigley and Mondelēz have backed the Chewing Gum Action Group, an association that helps cities cleaning gum and organises anti-littering campaigns, gum is still widely loved and people are still careless about what they do with it afterwards.

Even armed with the Terminators, Mexico City’s gum-removers need to travel with two large trucks that shoot water through high-pressure hoses, leaving telltale marks on the city’s epidermis. José Armando Cervantes Loesa, who oversees the operation, peers at one of the marks pensively: “Even so, the ghost of the gum remains, and we need to pass through, once again, with the washing carts.”

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