Now the onset of November and the prospect of December seem to centre on only one thing in Delhi: Air Quality Index or AQI. And that other related acronym, PM-Particulate Matter-with its two numerical appendages, 2.5 and 10. There is nothing quite so joyless as waking up to first check whether the capital is in Severe or Hazardous, or, if we are lucky, merely Poor or Very Poor. That the latter classification actually evokes relief is truly tragic.
