CHIANG MAI - Chiang Mai city retained its crown as having the world most polluted air on Tuesday, even as the number of "hotspots" in the northern province dropped sharply.
A satellite image issued by the Geo-Informatics and Space Technology Development Agency on Tuesday showed 17 hotspots in the province, a continued decline from 24 on Monday and 61 on Sunday. They were found in four districts, led by nine in Chiang Dao. None were in Muang district.
Despite the lack of hotspots in Muang district, Chiang Mai municipality was again the most polluted city in the world around 10.30am. Its Air Quality Index monitored by Swiss-based IQAir was 180, compared with 96 in Bangkok. The Thai capital was 19th in the global bad-air rankings.
Daily records compiled by the Environment and Pollution Control Office Region 1 over the previous 24 hours and released at 7am showed high levels of PM2.5 pollutants in two locations in Muang district, in tambon Chang Phueak, 94.3 microgrammes per cubic metre, and in tambon Suthep, 85.0.
The city's neighbouring Mae Cham district recorded 184.9 and Muang district in adjoining Lamphun province 113.8.
The office specifically warned Chiang Mai residents in tambons Chang Phueak and Suthep of the high risk to health from fine dust pollution, which also plagues neighbouring Lamphun, Chiang Rai and Mae Hong Son provinces.
Firefighters continued to battle forest fires burning in the northern provinces, assisted by aircraft dumping water over the area.
