About 90% of the hotspots in northern Thailand are caused by humans and PM2.5 atmospheric pollution in the region is expected to increase before it gets any better, said Director-General of the Pollution Control Department Pinsak Suraswadi.

According to the IQAir website today (Friday), Chiang Mai has the second worst air quality of any city in the world, with the quality measured at 177 on AQI, which means that the problem is affecting the health of everyone in the province.

Pinsak said that 90% of the hotspots were detected in conserved forests, with humans being the main culprit, adding that the problem trends worse from tomorrow until next Friday, with higher levels of dust reported in Chiang Mai, Lamphun, Sukhothai and Phitsanuloke.

He pointed out that there is a high concentration of sugarcane farms and sugar millers in Phitsanuloke, Uttaradit, Sukhothai, Kamphaeng Phet, Phichit and Phetchabun provinces and farmers have accelerated the burning of their crops as some millers start to shut down their operations.

Hotspots in Myanmar account for just 5% of the dust problem in northern Thailand, he said.

The Geoinformatics and Space Technology Development Agency (GISTDA), which conducted a survey of the western and norther regions, also confirms that burning of crops, such as sugarcane and maize waste, to prepare the land for the next round of cultivation, is believed to be the cause of the increased hotspots.

The setting up of a command centre in each province to deal with forest fires and the deployment of thousands of volunteers to fight the fires amount to treating the symptoms without addressing the root cause, said Pinsak, as he urged the public to watch out for people who start fires and alert the authorities.