Delhi tops the list of air pollution in the world, Dhaka at the fourth position

India's capital city Delhi tops the list of cities with the most polluted air in the world. Dhaka, the capital of Bangladesh, is on the fourth position in the list.

Pakistan and Vietnam are also in the list of top five polluting countries. This information was reported in the Air Quality Index (AQI) index of the air quality monitoring organization on Friday (November 1) at 9:30 am.

According to the index, Dhaka is ranked fourth in the list of polluted air cities with an AQI score of 141 at 8:50 am on Friday. According to the AQI index, today's air is classified as "unhealthy".

On the other hand, Delhi in India, Lahore in Pakistan and Hanoi in Vietnam are ranked first, second and third with AQI scores of 348, 211 and 197 respectively.

Basically an AQI score of 101 to 200 is considered 'unhealthy' for susceptible groups. On the other hand, an AQI score of 201 to 300 is considered 'very unhealthy' and an AQI score of 301 to 400 is considered 'hazardous', posing a serious health risk to residents.

AQI in Bangladesh is determined based on five parameters of pollution – particulate matter (PM-10 and PM-2.5), NO2, CO, SO2 and ozone (O3).

Particulate matter PM-2.5 is a collection of all solid and liquid particles in the air, most of which are hazardous. PM-2.5 causes a variety of diseases harmful to human health such as life-threatening cancer and heart problems. Besides, air pollutant NO2 is mainly produced by old vehicles, power plants, industrial establishments, cooking, heating and fuel burning in residential areas.

According to the World Health Organization, air pollution alone kills nearly 7 million people worldwide every year.