In the vast Indian interior, it is not unusual to see shoeless infants – whether walking barefoot to school or hopping around on makeshift sports pitches. Injuries are common and lead to infections such as hookworm and elephantiasis.

More than 250 million Indians live below the poverty line and footwear is usually a luxury. Tens of millions of children have no shoes. (By contrast, roughly 300m pairs of shoes are discarded in the US every year).

Now, two young athletes in Mumbai have come together to convert old shoes into new footwear for unshod schoolchildren in small villages.

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Green Sole has teamed up with schools and colleges to distribute remade footwear across states such as Odisha, Assam, Telangana and Uttar Pradesh. So far they have provided more than 150,000 pairs of flip-flops and slippers.

“We have also started retailing our recycled footwear through stores and online portals,” said one of the founders, Shriyans Bhandari. “Besides making footwear and distributing it, we are very proud of having set up a skill centre in Jharkhand, to train tribal women in recycling footwear.”

The duo is working with large companies such as Adidas, Sketchers and H&M to collect old shoes, and absorb the cost of converting them into new slippers for children. A donation of 200 rupees (£2.30) is enough to recycle one shoe. Shriyans says that his “ambitious mission is now to make sure that every person in the country has a pair of shoes by 2023.”

The hope is that footwear will encourage school attendance. Some children initially did not wear the flip-flops, storing them safely in a cupboard because they were precious. But more typical is the story of one 14-year-old girl called Radha. Her daily walk to school was a 4km round trip. In the summer heat, it was sometimes impossible to walk barefoot and her schooling suffered. Her new shoes have improved her attendance.

A proliferation of companies and social enterprises in India are working to repurpose and recycle old materials into new products and items of clothing, from Goonj, which revives garments and distributes to the needy, to HelpUsGreen which converts old flowers from temples and mosques into incense sticks, organic fertilisers and insulation.

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Code, started in 2016 by friends Vishal Kanet and Naman Gupta, is India’s first cigarette waste management company, turning butts into manure, and stuffing for cushions and toys. Pune based Aarohana Ecosocial started by Nandan Bhat and Amita Deshpande, in 2015, is converting plastic waste into fabric and then making handbags, accessories and home décor from it, employing local tribal people.

“For Indians recycling and upcycling are not new concepts,” says Shriyans. “Generations of Indians have converted old saris and bed sheets into quilts and dresses, repaired old radios and transistors and reused oil cans as planters. But then consumerism took over and the old tenets were forgotten.”

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