Geneva, Switzerland (BBN)-Bangladesh has been ranked fourth among 91 countries in the world when it comes to air quality, according to a study of World Health Organisation (WHO).

The study which was released on Wednesday also leveled Dhaka, Narayanganj and Gazipur – the capital and its two adjoining cities – among the top 25 cities with poorest air.

WHO revealed the information in its 2014 version of the Ambient Air Pollution (AAP) database consists mainly of urban air quality data of 1628 cities from 91 countries.

Pakistan has been ranked as the worst country in the grouping with Qatar and Afghanistan remained in second and third most air polluted countries.

The database shows Iran, Egypt, Mongolia, United Arab Emirates, India and Bahrain as the worst ten air polluted countries.

BBN/ANS/AD-09May14-8:30am (BST)