Mohammad Abrar wakes up coughing most mornings. It’s not yet dawn but New Delhi is already blanketed in thick smog when he sets off for work. By 4 am, Abrar, aged 50, reaches Seelampur, a small neighbourhood in the capital’s north-east suburbs, which is home to India’s largest electrical-waste market. The market’s narrow lanes are lined with small scrapstores overflowing with piles of broken computers, telephones, TVs, microwaves, washing machines, ACs and end-of-life batteries. Abrar is one of more than 50,000 informal workers, including women and children, who make a living sifting through thrown-out goods to recover valuable materials that...