ISLAMABAD: Pakistani cities of Lahore and Karachi ranked among the world’s most polluted city on Saturday morning, according to Swiss monitoring group IQAir, as dense smog blanketed the capital of the Punjab province and surrounding areas. Lahore ranked the second most polluted city in the world with an air quality index of (AQI) of 191, categorized as unhealthy, at around 2:30pm on Saturday. Karachi, in the country’s south, ranked 11 worldwide, with an AQI of 119.