Air Quality Monitoring in Bangkok - What's your PM 2.5 ?
AirVisual App screenshot : Chiang Mai tops the list (again! once more!) once more on 16 March 2024. Bushfires to blame. PM 2.5 at the time was 237 micrograms per cubic meter. Chiang Mai has featured on top of this list a few times in the last few years. including last year. While there are other factors, bush fires and farm field fires now seem to be the causal factor.
Air Quality Alert
Bangkok is known to have a very limited number of public parks. Fortunately, off the main streets, trees can still be found along the streets and in private properties. However, empty plots are slowly but surely disappearing, with people moving out to the outskirts of the city, and property developers moving in.
There is however a larger environmental problem : at least since 2018 we have reported on the excessively high PM 2.5 (smaller than 2.5 microns) levels during the cold season and into the hot season, the period between December and April. Bangkok regularly has levels above 150, but the area most suffering is the North of Thailand, in Chiang Mai and the provinces around it. For years now, high levels of PM 2.5, even above 300, have been noticed. Nowadays at least the Bangkok Post reports regularly about this issue, and one can monitor the pollution levels oneself (see below). Actually, it is possible to judge the severity of air pollution by looking at buildings in Bangkok in the distance.
The EPA of the U.S. states that higher levels can cause : premature death in people with heart and lung disease, nonfatal heart attacks, irregular heartbeat, aggravated astma, decreased lung function and increased respiratory symptoms. Personally, we noticed some stinging in the eyes when walking outside.
Fires as seen with NASA satellites in Thailand. Clearly there is even more slash and burn in Laos and Myanmar.
Do your know your 'personal' PM 2.5 level ?
You may be worried about the air pollution in your home or apartment. Nowadays some small devices can accurately measure the amount of small particles. We used for a few year a device by ACER (the computer company) which gives good results, though the app to save and record the data, is poorly developed. IQAir, the best known company to provide local outside readings around the world through its app AIRVISUAL, also sells a small device that you can use at home, priced around 300 U.S. Dollar.
We can state two observations : If you live up in the air, pollution levels seem to be much lower than at street level (own observation). In general, indoor pollution levels if windows and doors are kept closed most of the time, are also better than outside. For smokers : if you smoke, the small particle number will go through the roof, easily going above 500. It seems also hardly possible to lower the number with air purifiers.
Hatari Air Purifier ( HT-AP 12 )
We have used the above air purifier by Hatari (model HT-AP 12) since a few years, and it works very well. I think there is a newer model on the market now. Our advice : do not pay 20,000 Thai Baht for a Japanese or European made air purifier. Personal experience with Hatari shows it works very well. When levels of pollution inside the home are a bit high, it clears the air within 15 to 30 minutes often to below 5 microgrammes per cubic meter. You can buy an Hatari Air Purifier for less than 5,000 Thai Baht, and the filters are also cheaper than most, when they need to be replaced.
Why ?
Opinion article dd. 10 April 2023 in the Bangkok Post
Why is this happening and why is it seasonal ?
Of course, there are many causes of air pollution : the usual suspect are car and traffic, factories, airplanes, etc. Well, in Thailand as in most places in the world traffic is always congested, and factories produce products all year round. So, there is a reason why this air pollution occurs during the months December till April, and as is suggested above it are the many 'spontaneous' forrest fires, and fires initiated by farmers in the North of Thailand, and it the surrounding countries. Actually, when looking at the NASA images a few times, it is clear that Thailand does relatively well compared to its neighbours. However, prevaling winds will bring the fine particles into Thailand. At the period when Bangkok was targeted in 2023, it appeared westerly winds brought pollution from fires in Cambodia.
The main culprit appears to be 'slash and burn' agriculture, where farmers burn forest and leftovers from crops to clear their fields for planting new crops. In Thailand and surrounding countries, it is known which Thai companies are responsible in 'encouraging' farmers to burn their fields. However, their names are not publicly mentioned (see in article excerpt above), because prevailing laws consider giving negative comments about persons and companies as slander, making the perpetrator risking a penalty or even jail.
The message is clear : Time your visit, certainly when going to the North of Thailand. There are reports that number of tourists (this is after 'reopening' after Covid-19) have been reduced after an initial surge, possibly because visitors became aware of this issue.
Hopefully, when more local citizens and foreign visitors keep complaining, one day the issure will be addressed. Up to now, there are the usual promises by politicians that something will be done. In 2023 they even contacted the surrounding countries (!). However, this happens every year but not serious actions are taken. In Bangkok, water is occasionally sprayed to 'rain down' the pollution. Also some impressive machinery has been tested to suck out particles from the air in outside areas. While interesting, it is difficult to take these efforts serious.