New Delhi — Asia’s largest economy, China, has long had a reputation for smoggy skies. But these days, neighbouring India is fighting the far bigger battle with pollution: the South Asian country is home to the world’s 10 most polluted cities. Outside Indian capital New Delhi, Kusum Tomar knows the personal and economic price of breathing some of the world’s most toxic air. At 29, she learnt that pollution was the likely driver of the cancer growing inside in her lungs. She had never touched a cigarette. Her husband Vivek sold land to pay for her treatment. They borrowed money from family. Their savings slowly disappeared. “The government is thinking about the economic growth of the country, but people are dying of diseases or suffering from diseases,” Tomar said. “How can you grow economically when, within your country, your citizens are facing economic problems because of the air pollution?” India has long struggled to pull together the type of co-ordinated national approach that’...