Dhaka recorded an "unhealthy" air quality index (AQI) score on Friday morning (September 18), maintaining its position near the top of the global air pollution rankings despite the weekend reduction in routine commuter traffic.

According to real-time data from Swiss-based air quality monitoring organization IQAir, the Bangladeshi capital recorded an AQI score of 173 at approximately 10:30 AM, placing the megacity fourth on the list of global cities with the worst air quality.

The Malaysian capital Kuala Lumpur topped the global ranking with an AQI score of 210, followed by Kuching, Malaysia, in second place with a score of 187. Lahore, Pakistan, ranked third with a score of 184, while Kolkata, India, took the fifth spot with a score of 160. AQI scores among the top ten most polluted cities globally ranged between 103 and 210.

AQI Scale Breakdown and Health Advisory

Under international environmental monitoring standards, air quality indices are categorized into six distinct health risk tiers:

• 0 – 50: Considered "Good."

• 51 – 100: Classified as "Moderate."

• 101 – 150: Rated "Unhealthy for Sensitive Groups."

• 151 – 200: Classified as "Unhealthy" for the general public (Dhaka's current tier).

• 201 – 300: Marked "Very Unhealthy."

• 301 – 400: Categorized as "Hazardous."

Health experts advise vulnerable demographics—including children, the elderly, and individuals suffering from respiratory or cardiovascular conditions—to remain indoors during elevated AQI periods and recommend that the general public limit prolonged outdoor activity.