According to the US Air Quality Index, Karachi, the largest city in Pakistan, is the most polluted of the top ten major cities in the world.
According to the air quality index, the port city has 199 harmful particulates per cubic meter of air pollution.
It should be noted that an Air Quality Index (AQI) rating of 150 to 200 is regarded as unhealthy, 200 to 300 is more detrimental, and 300 and beyond is considered extremely dangerous.
Experts claim that the air is heavier in the winter than it is in the summer, which causes toxic particles in the atmosphere to migrate downhill and pollute the atmosphere. A layer of contaminated particles, including significant volumes of smoke and carbon, as a result, covers a metropolis.
According to specialists, the effects of the smoke released into the sky by industries, burning coal, trash, oil, or tires start to show themselves from the beginning of winter and last through the conclusion of the season.
As a result, air quality is significantly compromised in cold weather when air pollution reaches highly harmful levels.
Although the air in Karachi may be filtered by southwest winds coming from the sea, these winds are generally halted throughout the winter, according to experts.
A healthy atmosphere in such a circumstance is subject to rainfall, which washes out all contaminated particles. They observed that winds flowing from the northeast enhance the concentration of hidden dirty particles.
Ground-level ozone, particle matter, carbon monoxide, sulfur dioxide, and nitrogen dioxide are used as the basis for the AQI computation.