A rare occasion: Dhaka's air quality 'good' this morning

Dhaka's air quality has turned "good" due to the incessant rain triggered by Cyclone Remal.

With an air quality index (AQI) score of 38 at 9am this morning, Dhaka ranked 77th on the list of cities worldwide with the worst air quality.

When the AQI score is between 0 and 50, air quality is considered to be ‘good’, while between 50 and 100 is ‘moderate’, between 101 and 150 ‘unhealthy for sensitive groups’, between 151 and 200 is ‘unhealthy’, between 201 and 300 is said to be 'very unhealthy', while a reading of 301+ is considered 'hazardous', posing serious health risks to residents. 

India's Delhi, Indonesia's Jakarta and Pakistan's Lahore occupied the first three spots on the list, with AQI scores of 216, 173 and 162, respectively. 

AQI, an index for reporting daily air quality, is used by government agencies to inform people how clean or polluted the air of a certain city is, and what associated health effects might be a concern for them. 

In Bangladesh, the AQI is based on five criteria pollutants -- Particulate Matter (PM10 and PM2.5), NO2, CO, SO2 and Ozone. 

Dhaka has long been grappling with air pollution issues. Its air quality usually turns unhealthy in winter and improves during the monsoon.  

With the advent of winter, the city’s air quality starts deteriorating sharply due to the massive discharge of pollutant particles from construction work, rundown roads, brick kilns and other sources.

Air pollution consistently ranks among the top risk factors for death and disability worldwide. Breathing polluted air has long been recognised as increasing a person’s chances of developing a heart disease, chronic respiratory diseases, lung infections and cancer, according to several studies.

As per the World Health Organization (WHO), air pollution kills an estimated seven million people worldwide every year, largely as a result of increased mortality from stroke, heart disease, chronic obstructive pulmonary disease, lung cancer and acute respiratory infections.