The annual crop season in north Thailand is coming to an end. It seems the only good side-effect of the Covid-19 outbreak is a decline in the number of fires and plantation burnings in the past few months. The result of this is that Chiang Mai’s Air Quality has experienced a significant improvement, according to aqicn.org.
The website’s data shows that Chiang Mai air quality index reported PM2.5 levels of less than 100 particles per cubic metre for more than two weeks. 50 AQI is the general safety standard in Thailand (and 25 for the World Health Organisation upper limit of safe air quality. On some days in the middle of the highest readings the AQI reached about 500!
The AQI is a standard that indicates the level of air pollution.
• Level 0-50 means good air quality
• 51-100 means moderate quality
• 101-105 will affect sensitive groups
• 151-200 is slightly harmful to health
• 201-300 is highly harmful
• 301-500 means extremely dangerous
During the last two weeks, Chiang Mai’s air quality index has seen a decrease of more than 50%, compared to the AQI levels at the same time in last year.
For two days in a row the city scored dubious distinction of having the world’s worst air quality.
Smog, smoke and haze have been a widespread public health problem in North and Central Thailand for over a decade. It usually occurs from January to April, but is highest in March because of the very dry conditions which intensify the forest fires. It’s exacerbated by farmers who burn plantation waste to clear land for the next harvest season.