Dhaka's air quality still unhealthy despite rain

Dhaka, one of the most polluted cities in the world, ranked third-worst in the Air Quality Index (AQI) Monday morning, even though a nor'wester, coupled with rains, lashed different parts of the country, including the capital, on Sunday.

The AQI of the densely populated capital of Bangladesh was recorded 183 at 9:31am. 

Nepal's Kathmandu and Myanmar's Yangon occupied the first and second slots with AQI scores of 331 and 191 respectively. 

An AQI between 101 and 200 is considered "unhealthy," particularly for sensitive groups of people like children and elderly population. 

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. 

On Sunday, a nor'wester, accompanied by rain and gusty wind, swept the capital and other parts of the country. 

At least 12 people were killed in Gaibandha and Faridpur during the storm.

The tropical storm, the first of the season, also hit the capital around 6:30pm and lasted for a few minutes, according to the Met Office. 

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. Its air quality usually improves during monsoon. 

A report by the Department of Environment (DoE) and the World Bank in March 2019 pointed out that the three main sources of air pollution in Dhaka are brick kilns, fumes from vehicles and dust from construction sites.

Air pollution consistently ranks among the top risk factors for death and disability worldwide. 

Breathing polluted air has long been recognized as increasing a person's chances of developing 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.