Lahore has once again emerged as the most polluted city in the world, with its air quality classified as “unhealthy”, according to air quality monitoring platform IQAir, as Chief Minister Maryam Nawaz said the government was making efforts to address environmental issues.

In the past few years, air pollution has become one of the most pressing public health and environmental crises facing Pakistan. Various cities of the country, most notably Lahore, deal with smog, especially in the winter months. The phenomenon is attributed mainly to industrial emissions, vehicular pollution, stubble burning and air movement.

Lahore topped the list of the most polluted cities on Friday morning, with an air quality index (AQI) of 167, according to the IQAir live tracker, falling under the ‘unhealthy’ category, closely followed by Bangladesh’s Dhaka at 164 and Egypt’s Cairo at 158.

The provincial capital was the only Pakistani city ranking in the top 30 most polluted cities on Friday. The only other Pakistani city in the 125-city list was Karachi at 34th place with an AQI of 69.

According to IQAir, in Lahore, “PM2.5 concentration is currently 15.2 times the World Health Organisation annual PM2.5 guideline value”.

PM2.5 refers to fine inhalable particles, with diameters generally 2.5 micrometres and smaller. Of all air pollution measures, PM2.5 pollution poses the greatest health threat, according to IQAir.

According to the website, PM2.5 can enter the circulatory system and even the brain, causing serious health complications if long-term exposure occurs.

For those in Lahore, IQAir recommended avoiding outdoor exercise, closing windows to avoid outdoor air, wearing a mask outdoors and installing an air purifier indoors.

Meanwhile, in a televised address to senior officers in Lahore on Friday, Punjab Chief Minister Maryam Nawaz said the provincial government was making efforts to address environmental issues.

For the past eight years, she said, Lahore as well as some parts of Punjab would undergo a “smog shutdown” in September and October

“For three years now — I won’t say there is zero smog, but — there is less smog,” she said.

In January this year, Lahore was ranked as the most polluted city globally by IQAir with an AQI of 452. Earlier this week, a new analysis released by the European Union’s Copernicus Climate Atmosphere Monitoring Service (CAMS) ranked Lahore among cities whose ozone levels were “extremely poor”.