Smog returns: Bangkok ranked world’s 8th polluted city

Bangkok was ranked as the eighth most polluted city in the world this morning, according to air-quality monitoring website IQAir.

Bangkok registered an air quality index (AQI) of 141 on Thursday. The scale has six categories: 0-50 (good air quality), 51-100 (intermediate), 101-150 (unhealthy for some groups), 151-200 (unhealthy), 201-300 (very unhealthy), and over 301 (hazardous).

The 10 cities with the worst air pollution in the world as of 8am on March 20 according to IQAir were:

1. Kathmandu, Nepal – 188

2. Delhi, India – 176

3. Lahore, Pakistan – 156

4. Algiers, Algeria – 155

5. Hanoi, Vietnam – 155

6. Dhaka, Bangladesh – 151

7. Dubai, United Arab Emirates – 143

8. Bangkok, Thailand – 141

9. Wuhan, China – 138

10. Warsaw, Poland – 132

IQAir also listed top 10 areas in Thailand with the worst air quality on Thursday morning, as follows:

1. Samut Songkhram province – 163

2. Nakhon Pathom province – 156

3. Saraburi province – 153

4. Samut Sakhon province – 149

5. Phra Pradaeng district, Samut Prakan province – 146

6. Bang Sao Thong district, Samut Prakan province – 146

7. Nakhon Ratchasima province – 143

8. Bangkok – 141

9. Phetchabun province – 140

10. Samut Prakan province – 132

AQI measures six types of air pollutants, namely PM2.5 (fine particulate matter with a diameter of 2.5 micrometres or less), PM10, ozone, carbon monoxide, nitrogen dioxide and sulphur dioxide.