It’s daybreak in Guwahati and smoke billows into the sky as I take the wheel for my long drive back to Delhi. It is the last week of November, and a nip in the morning air is just enough to set off fog, or smog in this case. The smoke came from burning waste by the roadside. Although the city has a functional garbage collection system, households and roadside vendors burn dumps of leaf and plastic litter. And then there is road dust and ground-level ozone which adds to the deadly cocktail in the air. All this hasn’t deterred the morning walkers and runners, though pulmonologists have been putting out alerts that it is not the best time to go out for such physical activity.