India’s 900 million voters have completed the process of selecting their next leaders. Even as many of the country’s challenges and successes are litigated in the campaign process, a question mark still hangs over how the country can tackle air pollution. More than half a billion citizens breathe air that exceeds India’s air quality standards, all of whom are therefore living shorter lives.

Based on rigorous new scientific evidence, the Air Quality Life Index estimates that if every part of India were to meet national standards, life expectancies would rise by almost two years. Across the highly polluted Gangetic plain, this number ranges from four to six years. There is no question that pollution in the air is now one of India’s greatest public health challenges….