LAHORE: Lahore has once again topped the global charts as the world’s most polluted city, with an Air Quality Index (AQI) of 360 recorded on Sunday, exacerbating the persistent smog problem faced by its residents.
There appears to be no imminent relief in the form of rain, further compounding the issue.
The pollution levels varied across different parts of the city, with the AQI reaching alarming highs of 702 at the Polo Ground in Cantonment and 567 on Syed Maratab Ali Road. Other notable readings included 445 in Valencia, 395 in Johar Town Block A, 394 at the Ghazi Road Interchange, 537 at the Pakistan Engineering Service, and 368 over The Mall.
Despite the suffocating smog in Lahore, the weather in the twin cities of Rawalpindi and Islamabad, along with nearby areas in Khyber Pakhtunkhwa (KP) and Azad Jammu and Kashmir (AJK), experienced heavy rain on Saturday, leading to much colder conditions.
Murree welcomed its first winter rain, while light rain and snow were reported in various parts of AJK and KP. The mountains in Naran and Kaghan in KP also saw a fresh snowfall, creating picturesque winter scenes.
The Pakistan Meteorological Department (PMD) reports that a continental air mass is currently dominating most of Pakistan, with a shallow westerly wave affecting the northern regions. The forecast for Sunday indicated cold and dry conditions nationwide, with light rain and snow expected in isolated areas of Gilgit-Baltistan under partly cloudy skies. Fog and smog are likely to persist in the plains of Punjab and upper Sindh during the nighttime.
Similar weather conditions are expected to continue into Monday, with cold and dry weather across the country and potential fog and smog in parts of Punjab and Sindh during the morning and night.
The last 24 hours have seen dry weather in most areas, although light rain was recorded in Murree, Islamabad, and some regions of Kashmir, KP, and Gilgit-Baltistan. Muzaffarabad recorded the highest rainfall with 7mm.
With temperatures dipping to -7°C in Leh and -1°C in Skardu, the northern regions are experiencing a significant chill, prompting authorities to advise caution for travelers in foggy areas and for residents to prepare for the ongoing cold wave.
It is pertinent to mention here that rain plays a crucial role in mitigating smog and improving air quality through several mechanisms.
One primary method is the scavenging effect, where raindrops capture and absorb air pollutants as they fall through the atmosphere. This process effectively removes particulate matter and soluble gases from the air, cleansing the atmosphere as the rain reaches the ground.
Additionally, heavier rainfall can physically wash particulate matter out of the air and deposit it on the ground. This includes common pollutants like dust, pollen, soot, and smoke particles that contribute to smog. Rain can also facilitate chemical reactions that neutralize harmful pollutants. Since smog formation is accelerated by higher temperatures, a cooler atmosphere following a rainfall can help slow down the chemical reactions that lead to smog creation.
