ISLAMABAD: Pakistan’s Lahore once again topped global pollution charts on Monday, with toxic smog in the eastern Punjab province showing no signs of letting up.

Lahore and other plane areas of Pakistan’s Punjab province are prone to thick smog every winter as cold, heavy air traps construction dust, vehicle emissions and smoke. The smog crisis, which is spurred by crop burning, vehicle emissions and industrial pollution every winter, threatens public health and daily life.

According to Swiss monitoring group IQAir, Lahore topped the list of most polluted cities in the world on Monday around 10:00 am, with its Air Quality Index (AQI) measured at a “hazardous” level of 401. India’s capital Delhi followed behind at number two with an AQI of 262 while Pakistan’s commercial hub Karachi ranked at number four with an AQI of 165. 

Lahore recorded a PM2.5 of 276 µg/m³. The PM2.5 refers to floating particulate matter in the air measuring 2.5 micrometers in diameter or less that can be absorbed into the bloodstream upon inhalation.

“PM2.5 concentration is currently 55.2 times the World Health Organization annual PM2.5 guideline value,” IQAir said regarding the air quality in Lahore. 

Smog season begins in late October and peaks from November to January, lasting through February.

Earlier in October, the Punjab government conducted its first anti-smog gun operation, which helped lower the city’s unhealthy air quality levels. Anti-smog trucks sprayed fine water mist across the city to help settle dust and pollutants.

Smog can cause sore throats, eye irritation and respiratory illnesses, while long-term exposure increases the risk of stroke, heart disease and lung cancer. In the past, it has triggered lockdowns, hampered economic activities and resulted in the closures of schools and offices in Lahore and Punjab.