Air pollution engulfs Karachi with winter winds from Northeast

KARACHI: Karachi ranked 7th most polluted city of the world on the Air Quality Index (AQI) on Tuesday morning, ARY News reported.

Karachi was measured to have 177 reading of particulate matter on the air quality index.

Minimum temperature will remain 15-degree Celsius in the metropolis today, according to the Met Office.

The wind speed has been two nautical miles in the city from northeast direction, weather department said.

It is to be mentioned here that AQI as high as 151-200 is considered unhealthy, while an AQI reading between 201 to 300 is more harmful and AQI reading over 300 mark is 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 and making the atmosphere polluted. As a result, a layer of polluted particles, including large amounts of carbon and smoke, covers an area.

The smoke produced by factories or by burning coal, garbage, oil or tyres, enters the atmosphere and its impact appears at the onset of the winter and remains till the end of the season, experts said.

Although southwestern winds blowing from the sea in Karachi, work as a filter for the air, these winds remain mostly suspended during the winter, experts said.

The winds blowing from the northeast increase concentration of polluted particles, and a healthy atmosphere in such a situation is subject to the rainfall, which washes off polluted particles.