Lahore on Wednesday remained on top of the list of the most polluted cities in the world with an average pollution reading of 230, ARY News reported.
According to the air pollution data shared by the Punjab Environment Protection Department, Shahra-e-Quaid-e-Azam remained the most polluted area with a reading of 424.
The pollution in the air at Mall Road was recorded over 400 at the AQI. Lahore Cantt areas recorded 313 AQI reading. The caretaker Punjab government has advised the masses to wear facemasks while going to public places.
The AQI is calculated based on five categories of pollution: ground-level ozone, particulate matter, carbon monoxide, sulfur dioxide, and nitrogen dioxide.
AQI as high as 151-200 is considered unhealthy, while an AQI rating between 201 to 300 is more harmful and AQI over 300 is extremely hazardous.
Read more: Karachiites advised to wear masks amid worsening air quality
According to experts, air pollution level goes upward in winter, change in wind speed, wind direction and sliding minimum temperature increases air pollution.
The air becomes heavier in the winter as compared to summer, causing poisonous particles in the atmosphere to move downwards and making the atmosphere polluted. As a result, a layer of polluted particles, including large amounts of carbon and smoke, covers an area.