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Air Pollution in Thailand: The Comprehensive Guide to Understanding and Combating the Smog

In the past couple of months, Bangkok and Thailand as a whole have made the news almost every day for their harmful and, at many times, dangerous levels of air pollution. While Bangkok doesn’t get the worst of the pollution – that tends to impact northern cities such as Chiang Mai – air pollution is a big issue nationwide.

Two weeks ago, I first arrived in Bangkok with the intention of exploring the capital of a country I’ve heard so much about. While I’ve had a fantastic time here, it became apparent on the first day of my visit that air pollution here is a severe issue.

I lived in Seoul, South Korea, for seven years, and I’ve written articles on air pollution in South Korea. With the worst days in Korea seeing an AQI of over 250, I’m far from unfamiliar with poor air quality. In fact, it was these experiences with air pollution that led me first to begin this website almost three years ago.

However, when I first set foot in Bangkok, something felt different. This wasn’t the same kind of air pollution that I had become accustomed to after my time in Seoul. Rather, it felt like something else entirely. Not only are you dealing with city-wide or nationwide pollution, but there is also hyper-localised pollution that you’ll regularly come across while walking the streets of Thailand’s capital.

Before diving deeper into this article, I want to clarify that I’m not trying to deter anyone from visiting Thailand or living there. It’s a beautiful country, and I’ve had a great time during my (short) time here. However, similar to if you’re planning to visit or live in Seoul, it’s essential to know exactly what you’re in for. Air pollution is a life-threatening issue; you must be aware of it.

I hope that, armed with the knowledge in this article, you will adequately prepare for your time in Thailand. Knowing what to expect and how to deal with air pollution in Thailand makes it possible to protect your health and make the most of your time there. With that said, let’s get started!

This post contains affiliate links. For more information, please refer to my affiliate disclaimer

Information on this blog is for informational purposes only. Readers are encouraged to confirm the information herein with other sources. Furthermore, this information is not intended to replace medical advice from professionals. This website assumes no responsibility for the accuracy of the information, which is subject to change without notice.

Air Pollution in Thailand

Bangkok Air Pollution

Is Air Pollution an Issue in Thailand?

The short answer to this question is yes; air pollution is a big issue in Thailand. According to health authorities in the country, more than 1.3 million people have already suffered from air pollution-related diseases in 2023. What makes this stat particularly staggering is that this data was published near the end of March – only three months into the year.

Chiang Mai, a prominent city in northern Thailand, made the news earlier this month for having the worst air quality in the world, as measured by IQAir. While Bangkok’s air quality wasn’t as bad (much of the air pollution in the north comes from field burning), it was still far from healthy.

In Chiang Rai, the northernmost major city in Thailand, the air quality exceeded the WHO guidelines by 125 times – an almost unbelievable amount. Considering that no level of air pollution is safe, concentrations this far in excess are bound to have severe short-term and long-term impacts.

State Of Global Air reported that in 2019, over 32,000 deaths in Thailand were attributable to ambient particulate matter pollution (PM2.5). While more recent data is yet to be released, the trend is upward, and it’s very likely that in 2023, even more deaths will be attributable to air pollution.

Thailand Air Pollution Deaths

Number of Deaths Attributable to PM2.5 (State of Global Air)

A separate study carried out by Harvard University and King Mongkut’s Institute of Technology Ladkrabang found this number even higher, blaming air pollution for 49,000 deaths in 2018. While I don’t believe human lives should ever be measured with an economic metric, the impact on GDP is staggering and worth mentioning. The health impacts of air pollution cost the country an estimated $95 billion, which is 6.6% of the country’s GDP.

Said another way, and more worryingly, air pollution in Thailand has decreased the average life expectancy by two full years. In Bangkok, the risk of premature death was calculated to be 13% higher due to air pollution alone. These two stats alone should be enough to cause worry, and they leave out the many non-mortality impacts of air pollution.

All of this is to say that air pollution in Thailand is a grave issue. While the issue is often highlighted in cities such as Chiang Mai and Bangkok, it impacts the whole country – the annual average PM2.5 concentration per cubic metre should not exceed 10μg/m3 according to the WHO guidelines. Thailand’s nationwide average surpassed this and reached more than six times the recommendation, with an annual average of 64μg/m3 recorded.

What Causes Air Pollution in Thailand?

Chiang Mai Air Pollution

With air pollution being such a serious issue in Thailand, what is the cause of the issue? When I wrote my article about air pollution in Seoul, it was quite straightforward – depending on your source, about half of the air pollution is produced domestically, with the other half being blown across from the Gobi Desert and Mongolia, depending on the season. In Thailand, however, the issue is very different.

By its nature, air pollution is a transboundary issue, meaning it easily crosses borders between countries and impacts not only the country generating the air pollution but neighbouring countries too. Due to this, it’s often difficult to pinpoint exactly where air pollution comes from.

Since Thailand has many countries nearby with few natural barriers, such as oceans, it’s difficult to pinpoint if the issue is primarily domestic or not. With neighbouring countries such as Myanmar and Laos being primarily agricultural-based (and regularly using slash-and-burn farming), particulate matter can easily cross borders and become a regional issue. While the three governments are working together to tackle the problem, no major actions have been taken yet.

Despite much research, I’ve been unable to find any reports or studies on the transboundary burden of air pollution for and from neighbouring and nearby countries. However, most air pollution in Thailand is likely produced domestically – especially in southern cities such as Bangkok, where field burning has less impact.

Knowing the majority of air pollution in Thailand is produced domestically, what are the root causes? Well, this largely depends on the city and region in question. For example, 72% of the city’s air pollution in Bangkok was from combustion engines in 2022. On the other hand, in Chiang Mai, the most significant pollution source is field burning.

Chiang Mai Crop Burning

Crop burning in near Chiang Mai.

While this field burning causes the extreme pollution levels that earned Chaing Mai the title of ‘world’s most polluted city’, it doesn’t account for much of the pollution seen in the capital, as only around 5% of the pollution in Bangkok is attributable to field burning. Instead, much of the pollution from this burning spreads to nearby Myanmar and Laos.

While there are other contributing factors to air pollution in north Thailand, the majority is from crop burning. This is a big issue in Thailand because burning is often the cheapest and most effective way to clear fields for future crops. While overall, agriculture only accounts for just under 20% of the country’s air pollution emissions, it creates periods of very severe pollution between crop seasons.

Moving towards the capital, we have a more multifaceted issue. While the vast majority of air pollution ( > 70%) comes from the combustion engines found on cars, scooters, buses, and more, factories also contribute significantly. Of the PM2.5 contributions in 2022, around 17% came from factories in the capital. 5% came from field burning, and the final parts came from smaller, less impactful sources.

Health Effects of Air Pollution

Health Impacts of Air Pollution

Health effects of air pollution. European Environmental Agency.

Although it’s still often overlooked, air pollution is very dangerous and should always be considered – especially if you are travelling to or living in a country where this pollution is common, such as Thailand. 

While it would be easy to dedicate a whole article to the health effects of air pollution (which I have already done, and I recommend reading for more information), I will briefly touch on some impacts here so the full severity of the situation is understood.

Air pollution directly leads to at least seven million deaths globally per year, and it has also been found to decrease the life expectancy in Thailand by around two years. On top of this, air pollution has been found to damage every organ in the human body.

Perhaps more worryingly, air pollution has been found to impact not only physical health but also mental health. Long-term exposure to a range of pollutants, including PM2.5, has been linked to higher chances of depression and even suicide.

While the health impacts of air pollution in Thailand are still being explored, there’s no denying that it is extremely detrimental to human health, and we need to be wary. I started this website to bring more awareness to air pollution, and while there seems to be more attention nowadays than before, it’s frustrating how often it’s overlooked.

Whether you’re visiting short-term or long-term, it’s important to remember air pollution can and will impact your health. Take precautions, and ensure you are always aware of the local air quality before heading outside.

Seasonality of Air Pollution in Thailand

Chiang Rai Air Pollution

Air pollution in Chiang Rai.

As with many countries, air pollution in Thailand is very seasonal. This is especially true in the country’s northern regions, where crop burning usually occurs between December and April, leading to the extreme levels of air pollution that have recently made the news worldwide.

These same months tend to be the worst in the capital, Bangkok too. However, while this is partly due to the fires found in the north, it’s also due to the weather patterns during this period of the year. AQICN is a great source for historical air quality data, and it shows January, February, and to a lesser degree, March and December as being the worst months of the year for air pollution in Bangkok.

Bangkok Air Pollution Historical Data

Bangkok historical air pollution. Data from AQICN.

On the other hand, the months of May – September tend to have significantly better air quality, with the peak of summer (June and July) having significantly cleaner air than any other month. This trend doesn’t apply solely to the capital but can also be seen in the country’s northern areas, including Chiang Mai.

If you’re planning a trip to Thailand and worried about air pollution, visiting during the summer, if possible, is advisable. If this isn’t an option, try your best to avoid January – April, as these are the months of severe air pollution, especially in the north.

Chaing Mai Air Pollution

Chiang Mai historical air pollution. Data from AQICN.

While most media attention goes to PM2.5 (particles smaller than 2.5 microns in diameter), PM10 particles also largely follow the same trends. While they tend not to be as severe in concentrations or health impacts, these particles are also important to watch. Interestingly, other pollutants such as NO2, O3, SO2 and CO don’t seem to follow these same trends – at least not in Bangkok, where these sensors are present.

As you can see from the two images above, the seasonal impact of air pollution in Thailand is far greater in the northern regions. While there is still an obvious trend of worse air quality in Bangkok during January – April, the extremes are significantly lower than in Chiang Mai. This reinforces the research that field burning and wildfire smoke has far less impact on the air quality in Bangkok than in the northern regions.

From this data, it’s easy to conclude that air pollution in Thailand is highly seasonal. While air pollution in Bangkok won’t typically reach the same extremes as in cities such as Chiang Mai, June – September are by far the best months in regard to air quality.

What Is Being Done to Address Air Pollution?

Bangkok Palace

Bangkok on a day with low air pollution.

While the story may seem bleak, there is some good news. Due to the transboundary nature of air pollution, the governments of Thailand, Myanmar, and Laos met just last month to attempt to tackle the problem. While I haven’t been able to find news regarding the outcome of these meetings, the fact that talks are happening is a great start.

All three countries use slash-and-burn farming, significantly contributing to air pollution nationwide, especially in the north. Not only this, but the air pollution emitted from Thailand also crosses the borders into the neighbouring countries making this an issue the countries need to tackle together.

This may be a pessimistic view, but Thailand has a strong incentive to improve the air quality by whatever means possible. Despite being a high season for tourism in the country, hotels in Chiang Mai during April had only 45% occupancy – down from the usual 80%. Since tourism is such a large part of the Thai economy, there is a strong incentive to improve air quality, even if the impact on human life is the true cause for concern.

On a domestic level, actions are being taken, but the results are currently less clear. In 2019, Thailand and the Climate and Clean Air Coalition began an initiative which was, in part, designed to tackle air pollution. Part of this initiative was to assess the pollutants emitted from different sources and calculate their impact on health and climate change. From here, solutions to reduce emissions are to be evaluated.

Once this has been established, institutional reforms can be discussed between the organisation and the government if needed. The organisation will help the government with teams of experts and assist with coordination between local and national governments where necessary. Again, this is a change looking towards the future, but the groundwork is being done, which is a positive beginning.

Perhaps most importantly, the Royal Thai Government has prioritised air pollution and has a six-year plan (2019-2025) for addressing particulate pollution. While the plan is well-drafted, experts have said there need to be new laws and law enforcement to tackle issues as complicated as air pollution.

Overall, Thailand has laid a good foundation for tackling air pollution. The government and local organisations are aware of how severe the issue is, and they have created plans to help improve the air quality nationwide. While only time will tell if these plans are implemented and carried out effectively, this first step is much stronger than in many countries.

Understanding AQI

How to Check Air Pollution in Thailand

Screenshots from IQAir’s AirVisual app.

Thailand has an extensive range of air quality monitors located nationwide. Many of these monitors are managed by government organisations such as the Thailand Pollution Control Department and Air and Noise Quality Management Division Bangkok. A range of non-profit organisations also run monitors alongside educational contributors and more.

This wide range of monitors ensures that almost wherever you are in the country, you should be able to check the local air quality in Thailand. However, where can you access the data provided by these monitors?

While some user preference is involved here (which is why I wrote an article on the best AQI apps), I recommend one of the following two apps/websites. The two I recommend are IQ Air’s AirVisual and AQICN. AirVisual is a well-known app and, to my knowledge, the most popular AQI app out there. It’s also the app that I use myself.

AirVisual contributors and recommendations.

AirVisual has a few advantages. Firstly, it’s super easy to use and very straightforward. The AQI will be provided as both a number and a colour (green -> brown), and you can even find local images showing how visible the air pollution is. Most importantly, the app also provides some advice on steps to take to avoid exposure to air pollution.

IQ Air uses monitors from the aforementioned organisations and businesses, so its data is trustworthy and reliable. There’s a reason it has become the gold standard for air quality apps!

AQICN is a website-only air quality platform that I like to use for viewing historical data. It’s a more complex platform that can initially seem overwhelming. This is because the pollutants are divided into individual concentrations (as opposed to only an overall AQI), which can feel like an information overload.

AQICN Chiang Mai Air Pollution

AQICN Chiang Mai air quality.

However, when you want to identify the air pollution trends in Thailand, there’s no better platform – it’s the same platform I used for the historical data in the images above!

One note: whichever platform you use, make sure you use the U.S. EPA AQI. There are many different air quality indexes, which are not all equal. The EPA AQI is good because it’s more conservative than many other scales and is more universally used.

If you want air pollution insights on a more local level, check out these air quality monitors made in Thailand!

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Best Under $200
AirGadient ONE

An indoor air quality monitor with great performance.

* This link may be an affiliate link. I can earn from qualifying purchases at no extra cost to you.

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Best Outdoor
AirGradient Open Air

With dual-PM sensors, this monitor emphasises accuracy.

* This link may be an affiliate link. I can earn from qualifying purchases at no extra cost to you.

When Should I Wear a Mask?

Sleepnet Envo Mask Review

Pictured: Envo Mask, N95 respirator.

This is one of the most frequent questions I get regarding air quality. While checking the AQI on an app or website is easy, knowing exactly what each level means and what actions should be taken is harder. For this section, I will use the U.S. EPA AQI, which can be found on apps such as AirVisual and AQICN.

It is worth noting that Bangkok does have its own air quality index, which can be found here. However, from what I’ve been told and based on my own experiences, most travellers and ex-pats in Thailand prefer to rely on apps such as AirVisual as they are familiar and work very well in the country.

The U.S EPA AQI has six tiers, which are as follows:

  • 0-50 (green) – Little concern. The air quality is good.
  • 51-100 (yellow) – Acceptable air quality.
  • 101-150 (orange) – Unhealthy for sensitive groups. Consider taking precautions.
  • 151-200 (red) – Unhealthy air. Everyone should take precautions and avoid going outdoors if possible.
  • 201-300 (purple) – Very unhealthy air. Avoid outdoors wherever possible.
  • 301+ (maroon) – Emergency conditions. Air is extremely hazardous.

Another frequent question I receive is, ‘When should I wear a mask?’. The answer to this will vary for everybody because, ideally, we would begin to mask as soon as the air quality becomes ‘moderate’ or yellow. No level of air pollution is safe, and every increase in concentration has health consequences.

However, many people don’t want to mask unless the air pollution is severe. If this is the case, wearing a mask at 100+ AQI (orange) is a sensible step, as this is when you will begin to see the air pollution visibly. At levels above 200, you will seriously want to reconsider going outside and try to stay inside wherever possible.

If you suffer from asthma or another respiratory condition, you may begin to feel the impacts of air pollution at lower levels. For example, I have asthma and often begin to feel a difference around 70 AQI – at this point, I will don a respirator because I know I will start to cough if I don’t take any precautionary measures.

I will discuss this more in the next section, but it’s imperative to pick the right mask or respirator for the best protection. Simply wearing the generic KN95 and KF94 masks you find at many convenience stores and pharmacies generally won’t afford you sufficient protection.

How to Protect Yourself From Air Pollution in Thailand

Check the AQI Regularly

Air Pollution in Thailand

The most important step to avoid the worst consequences of air pollution is to be always aware of the air quality. While this can seem troublesome – no one wants to check yet another app, it’s an important step to take to safeguard your health.

As we discussed earlier, my recommended app is AirVisual. If you’re looking for something to use on your PC, the website AQICN is a good choice, but it can appear overwhelming initially. Either of these tools is fantastic, but if they don’t suit your needs, you can find a list of other great AQI apps here.

In a city like Bangkok, I recommend using an AQI widget on your phone’s home screen. Since air pollution is regularly an issue, having the reading instantly visible every time you use your phone is handy. If you have a smartwatch, you can do what I do: have an AQI widget on the home screen.

At the end of the day, it doesn’t matter how you check the AQI as long as you can do so quickly and easily. It can take a while to get used to, but I highly recommend checking the air quality every day before leaving the house and then occasionally throughout the day.

Avoid Going Outdoors When Possible

Air Pollution in Bangkok 1

Unfortunately, the best way to avoid the worst consequences of air pollution in Thailand is often the most unrealistic – to stay indoors whenever the air quality reaches hazardous levels. I say this is unreasonable because most people will have to work, go to school, or otherwise go outside daily.

However, the best way to avoid the serious consequences of air pollution is to stay indoors whenever possible. If you have plans that can be changed or tasks which can be delayed, it’s worth avoiding the outdoors on the worst days.

When indoors, be careful not to introduce outdoor dust. This means you’ll want to keep windows and doors shut while utilising an air purifier if you have one. If you’re driving, make sure to use recirculated air (generally, this is an option you want to avoid, but on days of strong pollution, you don’t want to introduce ‘fresh’ air if possible).

Get an Air Purifier

AirDog X5 Air Purifier Review

AirDog X5 air purifier

Even if you’ve shut yourself inside, some particles have likely entered. Furthermore, indoor air pollution is also an issue – more so when you’ve closed all windows to prevent outdoor particles from entering. 

If you regularly find yourself needing to close the windows to keep your indoor air clean, an air purifier is probably a worthwhile investment. While many air purifiers aren’t cheap, there are affordable options. If you’re keen, you can make your own Corsi-Rosenthal Box!

When purchasing an air purifier, ensure it’s rated for the room size you plan to use in. On top of this, not all air purifiers are equal, so I highly recommend checking out some reviews on trusted websites such as Wirecutter and Consumerreports.

Mask With a Respirator

Best Disposable Masks

If you do need to venture outside, you will want to be donning a respirator at all times. When I say respirator, I mean an FFP2, KN95 or KF94 at minimum, with an N95 being a significant upgrade over most of the former options.

It’s important to note that a respirator is essential when it comes to air pollution. Facemasks such as surgical masks and barrier coverings such as those certified to ASTM F3502-21 are simply too ineffective against ultrafine particles to be useful.

Devices such as KF94s, KN95s and FFP2s are a step above these masks, but their effectiveness is still limited. Not only are they generally loose-fitting due to the use of earloops, but they rarely provide the user with an adequate fit.

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Best Disposable N95
3M Aura (9205/9210+)

The best disposable N95 respirator you can buy.

* This link may be an affiliate link. I can earn from qualifying purchases at no extra cost to you.

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Best N95
Envo Mask

N95, with a unique gel seal. This respirator provides good protection.

* This link may be an affiliate link. I can earn from qualifying purchases at no extra cost to you.

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Best Half-Face N95

For anyone who prioritises protection, the ElastoMaskPro is a great choice.

* This link may be an affiliate link. I can earn from qualifying purchases at no extra cost to you.

Ideally, you’ll want to find a respirator using a headband. While fit testing is required for the best fit, studies indicate that even wearing an N95 without fit testing provides far superior protection to other ‘equivalent’ respirators. 

While the best respirator will depend on your facial shape and size, the 3M Aura (9205+, 9210+ and 1870+) has been found to provide the best fit on average. Therefore, this series of respirators is the safest bet for anyone without access to fit testing.

Use an Air Quality Monitor

Atmotube App

Atmotube Pro portable air quality monitor.

Although air pollution is often believed to be consistent across a city or region, this is far from true. Even between roads, there can be large variations in air quality – particularly on busier roads. Cities in Thailand also have many street vendors, which, while selling delicious food, often contribute to local air pollution levels as the smoke from cooking can often be overwhelming.

While the AQI from apps such as AirVisual is very useful for identifying overall air pollution, a portable air quality monitor is your only choice if you’re interested in pinpointing pollution hotspots to avoid. 

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Best Over $200
uHoo AQ Monitor

With 9 sensors, this monitor keeps track of everything.

* This link may be an affiliate link. I can earn from qualifying purchases at no extra cost to you.

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Best Under $200
AirGadient ONE

An indoor air quality monitor with great performance.

* This link may be an affiliate link. I can earn from qualifying purchases at no extra cost to you.

BreatheSafeAir Award
Award Logo
Best Outdoor
AirGradient Open Air

With dual-PM sensors, this monitor emphasises accuracy.

* This link may be an affiliate link. I can earn from qualifying purchases at no extra cost to you.

Note that both AirGradient monitors are made in Thailand, meaning the shipping fees are minimal and delivery times are great.

While pollution levels are ever-changing, having a monitor such as the Atmotube Pro will allow you to always be aware of localised pollution. If you regularly commute to work via walking or biking, this can be useful for identifying areas to avoid – or at least areas where masking is essential.

These devices are quite pricey, and they can be hard to justify. If this is the case, there are some lower-priced alternatives, but they’re not all accurate, so I recommend reading reviews before deciding on a monitor to purchase.


Thailand Beach

Thailand is a beautiful country!

Thailand has a rich history and is extremely lively, and I highly recommend visiting if you can. If you plan to live there, I hope you have a wonderful time! There are so many upsides to living in this exciting country.

However, there are some downsides too, and one of them is air pollution. Deaths related to air pollution continue to climb, and while preventative plans have been laid out, they appear to be minimally enforced or not at all currently. Be prepared, download the AQI app of your choice, prepare some high-quality respirators, and be flexible with plans depending on the air quality.

While it can be hard to find resources on air quality, I hope this post provided the answers you were looking for! If you feel something was left unanswered, don’t hesitate to contact me at [email protected]. I’m more than happy to help wherever I can!

Air Pollution in Thailand FAQ

Is Air Pollution Bad in Thailand?

According to IQ Air, Thailand is the 28th most polluted country globally. However, it really depends on where in Thailand you visit and when.

Where Is Pollution Worst in Thailand?

Air pollution is generally worst in the north, around cities such as Chiang Mai and Chiang Rai.

When Is Pollution Worst in Thailand?

Pollution in Thailand peaks around January – April and these months are best avoided if possible.

Do I Need to Wear a Mask in Thailand?

Yes. If you are visiting or living in Thailand you will want to ensure you always have respirators on hand.

Is Air Pollution in Thailand Dangerous?

Yes. Air pollution in Thailand leads to millions of hospitalisations annually and tens of thousands of deaths.

How Can I Check the AQI in Thailand?

I recommend AirVisual or AQICN for checking the air quality index in Thailand.

Read 1 Comments on 'Air Pollution in Thailand: The Comprehensive Guide to Understanding and Combating the Smog'

  1. Really appreciate your info. Myself and my wife, who is Thai, are visiting family and
    friends in the northeast part of Thailand. I am 82 and my wife is 77. I knew Thailand had
    a pollution problem, but didn’t realize it was this bad. I have a problem with asthma and
    also use a pacemaker. The last few days, when I wake up I have to cough out a bunch
    of dirty mucus type before I can breath o k. I am seriously considering cutting our visit
    short because I don’t want to end up in a scary situation. Again, thank you for your time
    and trouble to help folks out. I’ll make sure to pass along your article and website.
    Just a note; before I retired, I spent some time in Wellington, working at the American
    Embassy there. I’d love going back.
    O L Cole

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