'Alarming' levels of smoke, not smog engulfing Lahore: Punjab chief meteorologist.

As schools in Lahore remained closed on Thursday for the first time due to the prevalence of "smog" in the city, Punjab Chief Meteorologist Mahr Sahibzad Khan said that the current smoke levels should not be confused with "smog".

"Smog components become visible after smoke and fog combine. Until now, the fog has not developed," he said while talking to DawnNewsTV.

"Fog has its own criteria under which it develops: the visibility must reduce to less than 1 kilometre, the humidity levels must be more than 90 per cent, the air must be still and the sky clear. Only then are there chances for fog," Khan explained.

"These phenomena (required for fog) are not currently present. There is smoke, because of car and factory emissions, as well as transboundary smoke coming in from India due to crop burning. So the smoke levels have risen significantly owing to these factors. And there are components in the smoke that raise the air quality index. People start calling it smog, but it isn't. There are alarmingly high levels of smoke, however."

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Khan said that it had rained yesterday and there are chances of rain today as well. "The weather is pleasant and it seems it will be tomorrow as well," he added.

Lahore's Air Quality Index (AQI) appeared to have improved on Thursday from a day earlier, falling to 106 in the late afternoon which is within the 'Unhealthy for Sensitive Groups' category.

On Wednesday, Punjab Chief Minister Usman Buzdar had announced the closure of public and private schools in Lahore today after the sudden spike in smog levels from less than 200 to over 500.

From November 9-12 the city's AQI will be in the 'Unhealthy' category, the daily index shows.

'Terrifying'

Following the unprecedented measure of schools closure yesterday, journalists took to Twitter to express alarm at the constantly rising levels of air pollution.

The head of communications for Amnesty International, Rimmel Mohydin, criticised the government for continuously monitoring pollution levels and "never actually doing...