Based on the provided references, Bangladesh had the worst air pollution in 2023, specifically measured by the annual average concentration of fine particulate matter (PM2.5).
According to the IQAir data for 2023, Bangladesh ranked first among the most polluted countries. Its annual average PM2.5 concentration was recorded as 79.9 μg/m³. PM2.5 is a significant air pollutant composed of tiny particles or droplets in the air that are 2.5 micrometers or less in width. These particles are so small that they can enter the bloodstream and cause serious health problems.
2023 Ranking of Most Polluted Countries by PM2.5 Concentration
The reference provides the following ranking for the top countries based on their average PM2.5 levels in 2023:
| Rank | Country/Region | 2023 PM2.5 (μg/m³) |
|---|---|---|
| 1 | Bangladesh | 79.9 |
| 2 | Pakistan | 73.7 |
| 3 | India | 54.4 |
| 4 | Tajikistan | 49 |
Data source: IQAir World's Most Polluted Countries 2023
As the table shows, Bangladesh's PM2.5 concentration was significantly higher than the other countries listed, identifying it as having the most polluted air among those ranked in this specific dataset for 2023.
