Daily Times

LAHORE: On Tuesday, Indian capital city New Delhi remain on top of the list of the most polluted cities in the world having worst air quality, as Lahore ranks second.

According to the Air Quality Index, India’s New Delhi is first in the list with 335 index points, while Lahore remained second with 264 points.

Bangladesh capital Dhaka remained in the AQI list of poor air quality.

According to the reports of international media, burning of crop residue and garbage causes hazardous hike in environmental pollution in the region.

The AQI is calculated on the basis of five categories of pollution: ground-level ozone, particulate matter, carbon monoxide, sulfur dioxide, and nitrogen dioxide.

AQI as high as 151-200 is considered unhealthy, while an AQI rating between 201 to 300 is more harmful and AQI over 300 is termed extremely toxic.

According to experts, an increase in air pollution used to be recorded in the winter. 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 burning crop remnants, 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 gets to extremely dangerous levels, severely compromising the air quality.