Further musings on Thailand’s bad air quality

An Ominous Introduction

As you probably already know, Chiang Mai, in Northern Thailand, has the unenviable distinction of having the most polluted air in the world at certain times of the year, most notably during the stubble burning months between February and May. According to data from the World Air Quality Project, in the 2019 season, PM2.5 levels in the city rose to 282µg/m³ — the maximum safe level indicated by the World Health Organisation is 25µg/m³ — giving Chiang Mai an Air Quality Index (AQI) of over 296.


PM2.5 chart for Chiang Mai 2019 - Rob Gregory Author

Historical PM2.5 data for Chiang Mai during 2019. Green is good. Everything else is not.


At the time, things were so bad in the ‘Rose of the North’ as Chiang Mai is sometimes called, that I wrote a tongue-in-cheek blog about how you could literally eat the air, it was that thick. You can read it here if you are interested.

Thankfully, things have calmed down since then, although at the time of writing, Chiang Mai still had an AQI of 105 according to Airvisual.com, with PM2.5 levels standing at 37.1µg/m³, so not all that healthy for your average city-dweller.


AQI reading for Chiang Mai - 26 Sept 2019 - Rob Gregory Author

Air Quality Index for Chiang Mai at 3pm on 26 September 2019, the time when this post was written.


However, rather than focusing on pesky, seasonal micro-pollutants, today I want to discuss another, all pervasive, but often overlooked airborne contaminant that brings misery to the lives of millions on a daily basis. Yes, that’s right, Asian dust.


A Different Kind of Dust

Dust is everywhere and comes from many different sources, including I should point out, ourselves. Dead skin cells can account for a substantial amount of the dust that occurs in the home environment, especially in the bedroom. Other sources of dust include soil particles, plant and animal fibres, airborne pollutants, ash and pollen. Dust as we know it, is commonly reported in AQI measurements as PM10.

However, Asian dust is different to that found in other parts of the world. Asian dust is vicious, nasty stuff. It is the kind of dust that lurks in alleyways, tempting young children into strange cars with promises of sweets and cute puppies. It is the kind of dust that swindles old ladies out of their pension money. It is the kind of dust, that like your Uncle Steve, turns up uninvited on Christmas Day and refuses to help with the washing up after eating all of the mince pies. In short, it is dust with a grudge and you had better watch out because once it has you in its sights, then there is no hope of escape!


Air pollution in Chiang Mai during 2019 - Rob Gregory Author

Air pollution during the burning season in Chiang Mai, 2019.


My Life With Dust

I first came across Asian dust almost a decade ago and to tell you the truth, that first encounter nearly finished me off there and then. I’m a genteel sort by nature and the kind of person who likes to keep a tidy home. My batting average with regard to dust was pretty good at the time and friends often commented on the ‘show home’ conditions that I lived in. All that changed when I moved to Asia.

Within a day or two of unpacking, I noticed a grimy, grey-black substance on my writing desk. Further examination revealed the same stuff on the coffee table and my bookshelves, not to mention other parts of the house. I took to it with a feather duster and then a can of Pledge, which had always done the trick in the past and was amazed by the resistance of the alien fuzz to traditional cleaning methods.

Unlike the well behaved British and Antipodean dust that I was used to, this unusual and unruly beast was sticky and clung to the surfaces with the tenacity of a one-handed man on the edge of a cliff. When it did finally relinquish its hold, it stuck just as fast to the feather duster and cleaning rag as it had done to the desktop. After much flicking, rubbing and buffing, I finally had the house clean again — although the feather duster and cleaning cloth were never the same — and settled down to a bit of much needed and very cathartic writing.


Dust on a fingertip - Rob Gregory Author

My mortal enemy for longer than I can remember. Sticky and all-pervasive, Asian dust.


The following day, it was back! Not quite as thick as the day before, but there nonetheless and with an evil glint in its eye that promised that this was only the beginning of a game that would be played out over a span of months and then years. It was then that I realised that I had contracted Asian dust!

Since then, my life has been one endless battle with the sticky detritus of a thousand passing scooters and soil-coated flip-flops, and I know from bitter experience not to skip a day, because that will only make it ten times worse when I come to resume the fight the following day.


The Dust Gets Worse

Some years ago, I became involved with a little bar in Chiang Mai. It’s a bit like Hemingway’s but without the customers. Still, it is home and I am rather fond of the place. Like many bars in Thailand, it is open to the street and this is where my woes are compounded. Every day, we wipe the tables, chairs and shelves before opening and every day, by the time that we close, a new layer of Asian dust has accumulated on every surface that we own.

Recently, things have taken a turn for the worse, due to a building project that has begun along the road from us. Several times each day, trucks laden with dirt, drive past the bar and leave in their wake, damp soil and building spoil, which, when it dries out becomes… yes, you’ve guessed it, Asian dust! Now, instead of having to clean the bar once a day, it is a task that must be done every couple of hours. I must admit that I have a growing appreciation for the suffering of the Greek figure, Sisyphus, and feel like I am living in the Asian version of the movie, Interstellar, although in my case, Michael Caine is five thousand miles away and I don’t have a spaceship or a wormhole to crawl in to!


Dust on a table top in Chiang Mai - Rob Gregory Author

Believe it or not, this table was cleaned less than three hours before the photo was taken!


Till Dust Do Us Part

Dust is a real problem in Asia and one that is set to get worse, with the increase in car ownership, high density living and the consequent number of major building projects that are occurring in the region. PM10 pollution might not have the same fear factor as its 2.5 micron cousin, but to my mind it is just as damaging, both physically and mentally. After all, dust particles, no matter what size they are, have to be filtered out by the body, be it by nose hairs, mucus membranes or in the lungs themselves and the constant cleaning that must be done to maintain a habitable living environment does tend to wear you down over time.


Historical PM10 data for Chiang Mai in 2019 - Rob Gregory Author

Historical PM10 data for Chiang Mai during 2019. Green is good, but is it good enough?


In a few months, I will be leaving Asia, for hopefully less polluted climes and while there is much that I will miss about this wonderful and anarchic part of the world, Asian dust is one thing that I will be happy to leave behind.


For more information about air quality, see:



Air Quality Index (Wikipedia)