The Complete Guide to Air Pollution in Bangkok: PM2.5, Air Purifiers, Masks, and More

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I’m sure you’ve heard it. The pollution in Bangkok can be bad–really bad.

So bad, in fact, that the government is thinking about seeding the clouds to make it rain and knock down some of the pollution floating around.

I don’t know about you, but this worries me. Especially since I have two young kids.

My wife and I have been finding out ways to limit our exposure to the pollution, or PM2.5.

What is this PM2.5 that everyone’s talking about anyway?

I thought I’d share our tips and resources with you so that you can better protect yourself and your family.

If all you are looking for is a recommendation for place to buy air purifier, I’d recommend you to get it from SmartAir.

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What is PM2.5?

PM2.5 is any particle in the air that measures less than 2.5 microns. So the pollution itself isn’t PM2.5, it’s the size of the pollution that’s referred to as PM2.5.

You need to worry about this because this is the size of pollution that can get past nose hairs, into the lungs, and possibly into the circulatory system.

The particles are so small that about 40 of them can fit around the diameter of one human hair.

If you want a more scientific explanation of PM2.5, check out this article.

When Does It Happen?

Air pollution is likely to be a regular event in Bangkok during the cold season from November to February.

During this season, there’s a change in air pressure in the entire country. This results in less wind to blow away air pollution caused by cars, construction, and factories.

In the end, the pollution gets locked up in many parts of Thailand and creates health problems until the summer, when the wind starts blowing again.

During November to February, the price of masks and air purifiers are expected to significantly increase.

During the air pollution period, you may need to pay more than 6,000 baht to get an air purifier and wait for more than 2 weeks for it to ship.

However, you can get it at 3,230 baht with can be delivered within a few days.

In case you don’t have one yet, it’s better to stock up on air purifiers and masks before the air pollution hits Bangkok again.

Where PM2.5 Comes From

PM2.5 comes from many sources in and around Bangkok, although the exact cause is still unknown. Some experts believe the pollution is mostly from the following:



Bangkok is expanding the BTS and MRT lines all over the city. With all the contraction going on, it’s putting a lot particles in the air

air pollution bangkok construction
air pollution bangkok construction


Bangkok is known for its heavy traffic. With construction happening all over the place, narrowing roads and detours cause gridlock, and cars release more CO2 into the air.

Old Vehicles

A majority of buses in Bangkok have been in operation for over 20 years. The engines are no longer in a good condition and release smog everywhere they go.

And this smog doesn’t only come from buses, but construction trucks, cars, and tuk-tuks.

Agriculture and Industry

Thailand is still a slash and burn society. Each year, farmers burn their fields to destroy weeds and prepare for the seeding season.

Air pollution also comes from factories and power plants.

Although pollution from field burning and factories and power plants doesn’t happen in Bangkok, air currents blow pollutants from surrounding provinces into Bangkok.

Dangers of PM2.5

If you’re exposed to PM2.5 for long periods of time, you could wind up with a list of premature health concerns ranging from asthma to cancer and everything in between.

The unfortunate part about this is that “long-term exposure” isn’t really defined. Reports define long-term exposure as anywhere from months to years.

But here’s what Dr. Gerard Lalande, author of Stay Health in the Asian Tropics and Chief Medical Officer of Luma Health, said when we asked for his input on 2.5PM exposure time:

I believe there is a scientific and medical consensus on the harmful effects of fine PM as well as a definitive evidence that children, elderly and at-risk individuals are more prone to be affected.

2.5 PM have also been implicated in abnormal evolution of pregnancy as well as impacting negatively on the health of the children born from women exposed to air pollution during the pregnancy.

It is worth to highlight that there is no evidence of a safe level of exposure or a threshold below which no adverse health effects occur.”

Here are some of the health risks you can face if exposed to PM2.5. The AQI Level stands for Air Quality Index Level, or the amount of PM2.5 in the air.

I show you how to find the levels of PM2.5 in your area in the How Polluted is Your Area? section.

AQI LevelHealth DescriptorMeaning
0 – 50GoodSatisfactory-little or no risk
51 – 100ModerateAcceptable-health concerns for sensitive people
101 – 150Unhealthy for Sensitive GroupsDangerous to children and adults with lung disease or other respiratory issues
151 – 200UnhealthyDangerous to everyone
201 – 300Very UnhealthyDangerous to everyone with noticeable health effects
301 – 500HazardousEmergency conditions-everyone will be affected

Now that you know what PM2.5 is, where it comes from, and the dangers of being exposed to it, let’s look at how to protect yourself from it.

Government Action

The Thai government normally launches emergency plans to try and decrease the air pollution by:

  • spraying water from firetrucks
  • cleaning roads in polluted areas at night
  • banning field burning for two months in five provinces surrounding Bangkok
  • arresting drivers of cars that release black smog
  • creating artificial rain
bangkok fire truck
The Thai government has been using fire trucks like these to spray water into the air to reduce the amount of pollution.

How Polluted is Your Area?

You may not know it, but you could be living in one of the most polluted spots of Bangkok. But there are a few easy ways to check your area:

  • Websites
  • Apps
  • Monitors

Air Quality Index Websites

Below are three air index websites that you can use to check the quality of air in Bangkok. It’s best not to rely on one single website, but rather check out all three to be sure of their accuracy. gathers air quality data from five different sources to calculate the amount of PM2.5 in Bangkok’s air. They also give a seven-day air quality forecast based on previous data.

IQAir AirVisual

IQAir AirVisual gathers their air quality data from 15 different sources to calculate the amount of PM2.5 in Bangkok’s air.

They also offer a wide range of other data, including hourly PM2.5 forecasts, historical data, and seven-day forecasts.

You can even select a location closest to you to get the most accurate readings. monitors the air quality in Thailand only.

The design of the website is not the greatest, but they have a great deal of info for each area of Thailand, including Bangkok and the surrounding areas.

In addition to PM2.5, measures CO, NO2, O3, SO2, and PM10.

Pollution Watch Thailand

Pollution Watch Thailand is a Facebook group run by volunteers that in addition to regular reports on pollution also provide additional background information, videos and news about pollution in Thailand. A good source for anyone interested in more than ‘what’s the AQI today’ when it comes to pollution issues in Thailand.

Air Quality Index Apps

If you have to go outside, leave your house when air quality is at its best. This way you can see what the air quality is like where you live and plan your trips outside accordingly.

IQAir AirVisual App

IQAir AirVisual (mentioned above) has an app for iOS or Android. It’s a handy app that lets you select the nearest location to you and gives you up-to-the-second updates on the air quality in your area.

air visual

As you can see from my screenshot, we’ve been living in one of the most unhealthiest areas. The scary part is that we weren’t even aware of this until we downloaded the app.

We’re now starting to wonder if this has led to my youngest daughters allergies, and it’s why we’re moving in March.


Air4Thai is another app for iOS and Android that gives you up-to-second updates on the air quality in your area, but it doesn’t use any outside sources to help them gather their info.

Air4Thai shows very low readings compared to IQAir AirVisual, which has led to concern for some Thai netizens. Or is that IQAirVisual boosts up their readings because they’re selling PM2.5 monitors?

Air Quality Monitors

If you want to monitor your house for PM2.5, or take a monitor on the go in your car. If you don’t mind about the brand, you can buy PM2.5 monitor online at less than 2,000 baht online.

Here are a few monitors that could help you.

Makerspace Thailand

Makerspace Thailand has a portable PM2.5 monitor for 2,500 baht. Long-time Thailand blogger Richard Barrow does a great job of reviewing this portable PM2.5 monitor.

Richard takes it all over Thailand, including airports, airplanes, cars, cities, and more.

Laser Egg

If you have some more money to spend, you can order a Laser Egg. Laser Egg by Kaiterra costs $149. But you can’t buy them in Thailand. You’ll have to ship them in from overseas.


The IQAirVisual monitor goes hand-in-hand with their app and website. In fact, when you get one of their monitors you can opt to send results to their website, so that people in your area can see the PM2.5 levels as well.

This monitor will cost you $265–not cheap.

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Lazada has a list of PM2.5 monitors for sale but the lack of reviews makes buying one a roll of the dice. Prices range from 650 baht to over 3,000 baht.

How to Protect Yourself Outside

You can’t just barricade your family indoors. So here are a few things you can do to limit your exposure to pollution outdoors.


You might feel like you’re living in End of Days, but wearing the proper mask will reduce the amount of pollution that enters your lungs.

bangkok air pollution 3m masks
A lady in Bangkok wears a surgical mask to protect herself from the air pollution while working outdoors.

To find out why KN95 masks are important, or which masks you can use in their place, read this article by the World Air Quality Index.

But in order to work, masks must fit tightly and be rated to filter PM2.5.

Surgical masks will work but not as good as masks rated to filter PM2.5 because they don’t fit snug around your face, which means you’re breathing in unfiltered air through the gaps.

3M FFP3 Masks

When it comes to masks that filter out PM2.5, 3M 9332 masks are always the top performing masks available. They can remove over 99.6% of PM2.5.

I haven’t seen these masks for sale in Bangkok. But you can order them on Lazada.

3M KN95 Masks

Your next best option is the 3M KN95 masks. You can find these at 7-11 or Tops Market. They come in a blue and white box. These masks remove 97.5% of PM2.5 in the air.

You need masks like 3M’s KN95 mask or equivalent. You can buy KN95 masks online at Lazada. But when pollution is at its worst they sell out quickly.

Surgical Masks

If you can’t find masks rated to filter PM2.5, you can use surgical masks. But surgical masks won’t filter as much PM2.5 because they don’t fit snugly around your face.

Reports show that surgical masks can remove up to 60% of PM2.5 in the air entering your body. In a bind, surgical masks are better than nothing.

Surgical masks rarely sell out. You can find them at any convenience store or pharmacy in Thailand.

It’s best to stock up on 3M masks so that you have them when you need them. Or you can order them online. My wife just found some 3M masks on Lazada and had them delivered within 24 hours.

How to Protect Yourself Inside

We can’t control everything that’s happening outside of our homes, but we can control what’s happening inside.

Here are a few ways to reduce the amount of pollution getting in your home.

Invest in Air Purifiers

When it comes to air purifiers, don’t buy anything other than a HEPA air purifier.

Other systems may claim to be better, but research shows that HEPA systems are the absolute best for removing pollution particles from the air.

Although expensive, HEPA air purifiers can significantly reduce the amount of pollution in your home. And you don’t even need a top-of-the-line purifier.

Air Purifier Reviews

We have a separate article on how to choose a good air purifier in Thailand.

In short, you can get an air purifier from SmartAir. They have various models for different room sizes. The cheapest model starts at 3,800 baht and can clean air upto 40 sqm.

Another popular air purifier you can get in Thailand is from Xiaomi. Richard Barrow bought bought a Xiaomi Air Purifier 2 and posted a review on his website.

To summarize, he is happy with the result. It significantly decreased PM2.5 in his house.

You can order it from Lazada. It usually takes just a few days to deliver.

Note that the cost of air purifiers and masks tends to significantly increase when Bangkok has an air pollution problem.

In 2018, the increase was almost 100% of the normal price. And sometimes, they’re out of stock.

So if you plan to live here, it’s better to get one yourself before the price increases.

If you’re looking for a general overview of air purifiers on the market, and you don’t mind shipping on into Thailand, you can check out WireCutter’s review of air purifiers.

You might not be able to buy some of the air purifiers on their list, but you’ll know which specs they used to review each one, and then be able to look for those specs on air purifiers in Thailand.


Long-time China expat Dr. Richard Saint Cyr also has a myriad of air purifier reviews on his website.

Who better to listen to than a doctor who battled pollution in China for ten years and who publishes his findings about air purifiers online

Sprouts also has a great article on HEPA air purifiers and how they can protect you and your children in Bangkok.

They list other resources as well, but I’m not sure how easy it is to get what’s on their list in Thailand.

Where to Buy

In Bangkok, you can buy air purifiers on- or offline. Some places may offer a better selection than others. So be sure to check around.


Karsten, founder of ExpatDen, uses a SmartAir purifier which can be bought directly from their website. Their no-frills-get-the-job-done-purifiers are available for less than THB 4,000 and filter replacements cost around THB 600 (with other brands charging more than THB 2,000 for filters, which you are supposed to change every 6 months).


Lazada sells a variety of air purifiers as well. But they tend to sell out when pollution gets really bad in Bangkok.

Home Pro

If you’re looking for a one-stop place to pick up a purifier, check out Home Pro’s selection of air purifiers. They carry a variety of air purifiers for all budgets. One downside is that those are probably the first ones to sell out when pollution hits, so be sure to call ahead to check if the shop has any in stock.


Central Mall is the official retailer of Blue Air Purifiers in Thailand. Blue Air is one of the most recommended brands according to Wire Cutter. You can buy air purifiers through Central’s online shop. Central though is definitely on the pricier side of things when it comes to air purifiers.

Sizing Air Purifiers

The size of air purifier you need depends on the size and layout of your living space.

If you live in an open floor plan, you can get away with buying one large air purifier. But if you live in a space with many closed-off rooms, you need to buy smaller air purifiers for each room.

In order to get the right sized purifier, you need to calculate the square footage of the space you intend to keep the purifier in. Then you’ll compare that number to the rating on the purifier.

The general rule of thumb is to buy an air purifier rated for 20% larger than the space you need to purify.

So if your studio apartment is 750 square meters, you’d need an air purifier rated for 900 square meters.

If you buy an air purifier that is slightly oversized, you’re purifier won’t run as much, saving you costs on electric.

DIY Air Purifiers

Some people have made purifiers using fans and HEPA filters that have worked just as well as brand name purifiers.

If you search DIY HEPA air purifiers on YouTube a list of videos will come up.

Although the guy in this video is selling these homemade HEPA air purifiers, you can get HEPA filters and floor fans–the two materials needed–at Home Pro or Thai Watsadu.

Close Windows and Doors

You might like to open the doors and windows early in the morning to clear the stagnant air out your home or enjoy the crossbreeze instead of kicking on the ac.

thailand condo
That crossbreeze might feel good, but it’s doing harm to your lungs.

But by doing this you’re letting pollution into your living space.

It’s best to keep all windows and doors closed when PM2.5 readings are at unhealthy levels.

Keep Plants

Neither my wife nor I have green thumbs. Most plants we buy, die. But after I came across this TED talk about how to create clean air in your home, I thought I’d give plants another shot.

The three plants mentioned in the short video are:

  • Areca Palm
  • Mother-in-Law’s Tongue
  • Money Plant
The three plants that you should keep in your living space to create clean air.

These plants are all available at local Thai garden centers. They help filter the air and they produce oxygen.

But you have to buy them according to how many people are in your home. So watch this four-minute video and take notes to get the full benefits of these plants.

How’s About Other Province

Based on 2018, other provinces also have air pollution problems during November to February. But it was not as bad as in Bangkok, except for some provinces in the north, including Chiang Mai and Chiang Rai.

In Chiang Mai, the air quality level during the cold season is similar to Bangkok. The worse part is that it lasts until April.

The air pollution problem is worse in provinces like Chon Buri, Samut Prakan, and Samut Sakron where there are many factories.

The good news for those who live in the beach destinations in the Southern Part of Thailand including Suratthani, Hua Hin, and Phuket is that you are unlikely to be affected by the air pollution. It is always windy there.

Now, on to You

No matter which steps you take, be sure to protect yourself and your family. No one is sure how long this pollution in Bangkok is going to last, but let this guide be the beginning to your pollution preparation.

To prepare yourself, it’s better to invest in an air purifier. You will need it. You can buy it online.

If I’ve forgotten to add any resources, or if you have any tips or techniques to stay healthy from the pollution in Bangkok, share your advice with our community in the comments section below.

Featured image courtesy of Scotty_. Other images courtesy of octal, danebrian, [email protected], and noshit-mag.

John Wolcott is the global editor for ExpatDen. He's a New Jersey native who now lives in Bangkok with his wife and two daughters.

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