Lahore has once again topped the global ranking of the world’s most polluted major cities, according to air-quality monitoring platform IQAir.

On Friday morning, Lahore recorded an Air Quality Index (AQI) of 167, placing it in the “unhealthy” category. Bangladesh’s Dhaka followed with an AQI of 164, while Egypt’s Cairo recorded 158.

IQAir reported that PM2.5 was the dominant pollutant in Lahore, with concentrations reaching 15.2 times the World Health Organization’s annual guideline value. Fine particles such as PM2.5 can penetrate deep into the respiratory system and are associated with serious health risks from prolonged exposure.

The worsening air quality has renewed concerns about smog in Lahore and other parts of Punjab. Major contributing factors include industrial emissions, vehicle pollution, crop-residue burning and weather conditions that limit air movement.

Punjab Chief Minister Maryam Nawaz said the provincial government was taking steps to address environmental problems and said Lahore and parts of Punjab would undergo a “smog shutdown” during September and October.

IQAir advises Lahore residents to limit outdoor exercise, keep windows closed during periods of poor air quality and use protective measures outdoors.