Karachi's AQI teeters on edge of 'very unhealthy' level, Lahore tops pollution chart. Port city records AQI value of 197; Multan becomes country's second most polluted city ...

As the chart shows, for PM2.5 concentrations up to 60 microgram per cubic metre (µg/m3), AQI increases by 1.67 for every 1µg/m3 increase in PM2.5 concentration.

Thus one can only work towards a solution where the AQI levels dip down from very poor to poor and then finally good so that people can breathe. Lower AQI means fewer pollutants in the air.

When AQI reaches a level designated as Poor, GRAP I, which imposes some restrictions, kicks in. When AQI is tagged as Very Poor, GRAP II comes into play, and so on to Severe, and Very Severe ...

A Chicago Air Quality Alert has been extended through Friday as smoke from Canada wildfires has pushed the AQI into unhealthy levels across the region. Latest U.S.

New Delhi ranked as the world’s most polluted city on Wednesday morning as residents in the Indian capital woke up to a thick blanket of haze, marking a severe air emergency. The pollution led ...

The AQI readings below 100 are considered to be satisfactory for breathing, under 200 are marked “poor”, while the 400-500 range mark pollution levels as "severe" in an area.