The once City of gardens and culture capital of Pakistan, Lahore has been ranked fourth among the world’s most polluted cities on the global Air Quality Index (AQI) on Saturday.
It is to be noted that AQI as high as 151-200 is considered unhealthy, while an AQI reading between 201 to 300 is more harmful and AQI over 300 mark is dubbed extremely hazardous.
According to experts, the air becomes heavier in the winter as compared to summer, causing poisonous particles in the atmosphere to move downwards, which ultimately the atmosphere polluted. As a result, a layer of polluted particles, including large amounts of carbon and smoke, covers the city.
Besides, the smoke produced by factories and by burning coal, garbage, oil or tyres enters the atmosphere and the effects of this appear at the onset of winter and remain till the season’s end, experts said.
Thus, air pollution reaches extremely dangerous levels in cold weather, severely compromising air quality.
The AQI is calculated based on five categories of pollution: ground-level ozone, particulate matter, carbon monoxide, sulfur dioxide, and nitrogen dioxide.
Other cities measured on AQI include, Bahawalpur was measured to have 327 hazardous particulate matter, while the reading of Lahore was 194, Rawalpindi 189, Raiwind 170, Karachi 167, and Multan 165, according to the air quality index.