Lahore was ranked the second most polluted city in the world in terms of air quality on Sunday, according to air quality monitoring platform IQAir.

The Air Quality Index (AQI) is a measure of the concentration of various pollutants in the air, such as fine particulate matter (PM2.5), coarse particulate matter (PM10) and nitrogen dioxide (NO2), and ozone (O3). Any IQAir AQI ranking above 150 is considered “unhealthy” and above 200 is considered “very unhealthy”.

The AQI reading for Lahore stood at a very unhealthy 189; it was just beaten by Delhi, which registered a reading of 212 around 7:30pm.

Additionally, levels of the pollutant PM2.5 were measured at 109 microgrammes per cubic metre of air (μg/m³), 21.8 times higher than the World Health Organisation’s annual PM2.5 guidelines.

PM2.5 particles are floating particulate matter in the air measuring 2.5 micrometres in diameter or less, according to IQAir. PM2.5 is so small that it can be absorbed into the bloodstream upon inhalation.

IQAir recommended on its website that residents in Lahore avoid outdoor exercise, run air purifiers and prioritise wearing masks. It also recommended closing all windows to avoid dirty air from outdoors.

Lahore has historically dealt with smog and poor air quality in the winter months.

Around this time last year, the air quality in Lahore was recorded at 394 amid the smog crisis, primarily fuelled by crop residue burning and industrial emissions. The smog caused widespread health issues among residents, including coughing, breathing difficulties, eye irritation and skin infections.

To combat smog this year, the Punjab government has introduced ‘smog guns’, with Punjab Senior Minister Marriyum Aurangzeb stating that they were already in use across Lahore.

“Through this modern machine, tiny droplets of water are sprayed into the air to combat smog,“ she explained. “The water mist helps clean pollution and dust particles present in the atmosphere. This modern machinery is also being used in countries like China, India, and others to reduce smog.”