Lahore tops global pollution list as reported readings diverge

Lahore was ranked the world's most polluted city in IQAir's global monitoring on Friday, 6 November, with the Pakistani outlets that carried the ranking reporting different air quality index readings for the same day.

Daily Times reported Lahore's AQI at 352 and said IQAir classified the city's air as extremely unhealthy. The report placed Karachi sixth worldwide at 170, the only one of the five to give a reading for the southern port city. Lahore's figure was more than twice Karachi's in that account. Daily Times said the numbers measured particulate matter, that higher values point to poorer air, and that the reading indicated conditions hazardous to public health.

24 News HD reported Lahore's reading at 360 and Daily Ausaf reported 458, the highest of the three. All three reports put Lahore in first place. None stated the hour at which the reading was taken, and none explained the gap between the numbers.

Pakistan Observer carried the same first-place ranking and described choking smog in its headline but gave no reading.

Minute Mirror did not carry Friday's ranking. It reported that monitors of the Punjab Environmental Protection Agency recorded an average AQI of 186 for October, against 218 in the same month last year, and said a pollutant-by-pollutant comparison showed where the improvement came from.

Minute Mirror described the pattern Lahore goes through at this time of year: the rice harvest ends, the nights turn cooler and a grey haze settles over the city for weeks. Schools close, flights are delayed and hospitals fill with patients who cannot stop coughing. The outlet said the episode had come to be accepted as a season of its own.

IQAir's platform tracks pollution readings in cities worldwide. Daily Times said the figures were published on Friday and that the platform's assessment placed Lahore at the top of the international list and Karachi among the six most polluted locations.