Karachi, Lahore among cities having most polluted air
- By Web Desk -
- Jan 20, 2021
KARACHI: The port city has been ranked at number four and Lahore at five among the world’s most polluted cities due to the soaring level of hazardous particles in air on Wednesday morning, ARY News reported.
According to the Air Quality Index (AQI) Pakistan has been among the countries with unhygienic air quality.
According to the air quality index the level of the hazardous particulate matter in most of the cities found above 250.
The reading of hazardous particulars in Faisalabad was recorded 290, in Karachi 212, Islamabad 204 and Lahore 203, according to the air quality report.
AQI as high as 151-200 is considered unhealthy, while an AQI between 201 to 300 is more harmful and an AQI over 300 is dubbed extremely hazardous.
According to an expert, an increase witnessed in air pollution in winter, change in the wind speed, wind direction and sliding minimum temperature increases air pollution, he said.
According to experts, the air becomes heavier in the winter as compared to summer, causing poisonous particles in the atmosphere to move downwards and making the atmosphere polluted. As a result, a layer of polluted particles, including large amounts of carbon and smoke, covers a city.
The smoke produced by factories and 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 to extremely dangerous levels, severely compromising the air quality.
Although southwestern winds blowing from the sea may work as a filter for the air in Karachi, these winds remain mostly suspended during winter, experts said.
They noted that winds blowing from the northeast increase the concentration of hidden polluted particles, and a healthy atmosphere in such a situation is subject to rainfall, which washes off all pollutants.
The AQI is calculated based on five categories of pollution: ground-level ozone, particulate matter, carbon monoxide, sulfur dioxide, and nitrogen dioxide.