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Air Pollution in Seoul – What You Need to Know

Today, Korea’s AQI reached over 150, an amount considered very unhealthy by the American Environmental Protection Agency.

Everyone may experience more serious health effects’ to the effect of smoking over ten cigarettes. Even a normal day has an equivalent health toll as smoking 6 cigarettes.¹

Although the air pollution in Seoul today was in greater than normal, there is no denying that air pollution in Seoul is something that you need to consider. Whether you are travelling to the country or living here, air pollution is always something that should be considered.

8.8 million deaths are caused by air pollution every year, and it affects virtually every cell in the human body.

Air Pollution and Noncommunicable Diseases

With dangers like this, you would think that the issue would be something that everyone is aware of, and that is commonly discussed. However, there are a surprising amount of foreigners and Koreans alike who are either incorrectly educated on the matter or don’t believe it to be a big health concern. However, air pollution is a big danger.

If you live in South Korea, and especially Seoul, then air pollution is something that you should be constantly aware of. It’s one of the leading causes of deaths worldwide and it has become a critical global issue. Further, it’s something that, provided you take the right steps, can easily have its impacts minimised.

This post is focused on air pollution in Seoul, and Korea in general. If you are living in Korea and looking for the best fine dust masks, please refer to my post on the best fine dust masks in Korea.

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.

Purchase fine dust masks in Korea.

Air Pollution in Seoul

Seoul Air Pollution Spring

Air pollution in Seoul in late May.

Rarely does anyone talk about the air. Sure, it is covered by the media at times, but the seriousness of the issue is often avoided. In fact, until recently, coal power plants were still being built. Coal and oil power plants are set to shut down partially when pollution reaches PM2.5 50 µg/m3, but even today the PM2.5 peaked far higher than that

Air pollution leads to over seven million premature deaths a year around the world, including 600,000 children. To put that figure in context, that’s more deaths every year than the combined total of war, murder, tuberculosis, HIV, AIDs and malaria.²

Watching the media here, it seems more and more common to find articles about air quality. Air quality which is now ‘some of the worst in the world’. It seems like not a day goes by without new articles and warnings arising. However, despite these warnings, there is still not that much consideration for the air quality.

As a foreigner in Seoul, it is especially hard to find information in English about the current state of the air in Korea, and how to deal with it. As such, I intend for this post to spread some awareness about the different factors of air pollution, the risks associated with them, and how you can minimise the effects.

While the air pollution in Seoul may not be as severe as that experienced in other cities around the world, it is important to not discount air pollution. It’s something that is dangerous in almost any concentration, and Seoul is often well above the WHO guidelines.

What Causes Seoul Air Pollution?

Air Pollution Causes

This is a highly controversial question that often results in heated arguments. Often the blame is placed on China. Just as often though, the blame is also placed on Korean domestic pollution. Especially by China.

Recently, the South Korean government has approached China with the plan of creating artificial rain over the Yellow Sea to help prevent pollution in Seoul.  However, while it is true that much of the bad air comes from China, it isn’t the only cause of the problem.

While the previous argument might suggest that Korea’s own emissions are mostly to blame, other studies have, however, confirmed that China’s emissions have substantially undermined South Korea’s air quality. An older study, conducted between August 2002 and December of 2003, provides solid evidence for transboundary movement of pollution from China to South Korea… This research found that huge seasonal spikes of airborne chemicals associated with residential biomass and coal-burning ovens in China accounted for as much as 82% of those measured in Seoul, due to prevailing westerly winds blowing pollutants over the Yellow Sea. A more recent study conducted on the Western coast of Seoul from June 2009 to May 2010 also found strong evidence that transboundary pollution from China corrupted South Korea’s air quality.³

While some research (such as the above) puts a large amount of the blame on China for Korea’s air pollution, it’s not that simple. When you also add to it the fact that FDI in China (from Korea) accounts for a large percentage of total Chinese FDI, it begs the question – who is accountable? Other studies have also claimed that Chinese air only accounts for 30 to 50% of the pollution in Seoul.

Finding the original source for air pollution is incredibly complicated. Even if large amounts of pollutants come from China, it’s not as simple as blaming the country. With many (non-Chinese) companies using production facilities there, large FDI and even natural causes (such as yellow dust), there’s really no clear cut conclusion.

Learn more about respirator filtration mechanisms & MPPS.

Who is Responsible?

Seoul Air Pollution Influence from other Countries

Influence from Neighbouring Countries by KOSAE

Whichever number we choose to believe though, Korea is at least partly (and possibly primarily) responsible for the unhealthy air, both due to FDI in China and domestic pollution. The issue with the air pollution coming from China is that it can’t be combated by Korea alone. This is a problem which must be tackled together – as with the proposed rain project.

However, the Korean government is not innocent. A study done by Korea University scientists indicates that policy failures are also to blame. In fact, while pollution has been decreasing, the relative risk of death from exposure to PM2.5 and PM10 particles has increased. While the government may be working on increasing air quality, the health effects are not being targeted.⁴

While finding the source of the problem is important, the vital step is to target the health problems and find solutions to the growing issues. Further, even if the majority of pollution does come from China, Korea has little influence as to what happens in China. Rather, while Korea discusses options with China, it is important that domestic solutions are also being formed. 

The research by the Korea University scientists also went on to say that the mortality associated with dust was actually greater when the days affected by Asian dust were excluded. Days of Asian dust are generally covered more by the media, and general awareness is greater.

More masks are purchased, and activities are restricted. Due to this increased awareness on days of Asian dust, the mortality rate is actually lower than on a day unaffected by the dust.⁵

The fact remains that not enough steps have been taken to reduce pollution and fine dust in Korea, and especially Seoul. Only recently has KIHASA (Korean Institute for Health and Science Affairs) developed ‘Korea’s New Comprehensive Plan on Fine Dust and Its Implications for Policy and Research’ with the September 26 measures.

These measures are aimed at cutting fine particular emissions by 30% by 2022.⁶ The plan outlines steps for a less polluted future. However, the outcome and actual results remain to be seen. The government needs to keep a strong stance towards reducing emissions and needs to remain active in their push to move toward a cleaner future.

Real-World Testing

Seoul Air Pollution 1

Seoul air pollution over 2019 and 2020. AQICN.

While it’s good to discuss research and reports (and frankly, it’s quite interesting), I also wanted to look into the air pollution in Seoul in a bit more detail. To do this, I used a portable air pollution monitor that I recently received from Plume Labs.

The accuracy of this device has been found to be within 5-10% of the actual pollution conditions. While it isn’t always totally accurate, it is usually very close. If you are interested in reading more about the device (including the accuracy), I covered it all in my Flow 2 review.

This device uses the Plume AQI, which tends to have stricter thresholds. Therefore, the colour ratings (such as yellow, orange and red) tend to be more easily reached than with the Korean Government’s CAI.

After walking around the city with the device in early June, I found that the air pollution readings tended to be higher than the official ratings. This is likely due to the fact that I was measuring the air pollution on a street level, often near busy roads.

Air pollution has been found to be worse around busy roads, and there are many very busy roads in Seoul. The issue is that because of the amount of traffic, the actual air pollution that you are breathing is often worse than what the local monitors show.

Flow Air Monitor

Walking around Korea University one night, I found that the air pollution was exceptionally bad. The official rating was 136 at the time – a rating that is hazardous, but not considered severe. However, after walking around the area I found the air quality to be significantly worse than I had imagined.

Of course, the air quality in Seoul varies a lot. There are days when it is very clean. But on the flip side, there are also days when the air pollution is very bad. For this reason, it’s important to always be prepared and ready. If you are considering living in Seoul long term, make sure that you are aware of the dangers and have measures in place to reduce your exposure.

Check out the Flow 2 Personal Air Pollution Monitor.

Air Pollution Seasonality

Seoul Air Pollution 1

The image above from AQICN shows the air pollution in Seoul over 2019 and 2020 so far. From the image, you can easily make out which months were the worst, and which were the best.

From the above table, it’s quite obvious that the worst months are those earlier in the year. January, February and March all show a higher number of days with red or greater levels of air pollution. Towards the middle of the year, the air pollution is generally less, and the best months for air quality are August-October.

Why is this? Well, it’s due to a few reasons. The first is Yellow Dust (sometimes named Asian Dust). This is the dust that gets pushed across Asia by the wind. Much of the dust originates in deserts in China and Mongolia, and it hits Korea in the spring months. It is especially heavy in March.

During the summer months, there is often more rain in Seoul. Rain has a cleansing impact on air pollution as it often catches the pollutants and brings them down to the ground. For this reason, the summer months are the cleanest of the year.

While there are exceptions, you can generally expect the air to be relatively clean throughout the summer months. During the winter and spring months, the air quality is usually significantly worse.

Effects on Health

Air Pollution Deaths

It is worth mentioning that while short term effects do indeed exist, medium-length exposures (31 days or less) and long term exposure are far more dangerous. If you are a tourist coming to Korea for under 31 days, the air effects will be far less damaging than they will be for a long-term resident.⁷

If you are a short term visitor to Korea, keep an eye on the AQI and wear masks on bad days. However, unless you have a prior heart or lung condition, short-term exposure to the air is unlikely to cause serious issues.

Air pollution leads to over seven million premature deaths a year around the world, including 600,000 among children. To put that figure in context, that’s more deaths every year than the combined total of war, murder, tuberculosis, HIV, AIDs and malaria.²

A recent report found that ‘Each 10-µg/m3 elevation in fine particulate air pollution was associated with approximately a 4%, 6%, and 8% increased risk of all-cause, cardiopulmonary, and lung cancer mortality, respectively’.⁸ At the past five days average PM2.5 reading of 77.6 μm/m³, this is a 31% increase in all-cause mortality, 46.6% increase in cardiopulmonary mortality and a 62% increase in lung cancer mortality.

On top of this, air pollution was recently found to have effects on every organ on the body. Further than this, it has been found to affect virtually every cell in the human body. In another recent study, air pollution has been linked to bipolar disorder, depression, and even suicide.

Air pollution is an extremely serious issue and it’s something that you need to be considering if you live in South Korea. Learn more about the effects of air pollution on health in this post.

Understanding AQI

Seoul Air Quality

Air pollution standards as given by the Seoul Government.

First seeing the air quality readings can be very overwhelming. From the PM 2.5 readings to the carbon monoxide, there is a lot to take in. I have been in this situation before too, and I know how hard it can be to understand everything!

With that being said, it’s not as hard to understand as it seems at first glance. Generally, there are only a few readings that you need to keep an eye on. However, it is worth knowing what all of the different readings mean.

It is also important to note that AQI is not a single universal rating. Different countries and platforms use different AQI calculations and they are not all the same. The system that Korea uses, and the system that they use to measure air pollution in Seoul is different from others.

Check this post for a comparison of the best AQI apps.

Korean AQI Rating

CAI Seoul Comprehensive Air Index

Comprehensive Air Index – AirKorea.

The air quality index in Korea, and in turn, the AQI used primarily in Seoul, is a calculation based on the concentrations of 6 different pollutants. All of these pollutants can be harmful in excess, and each can impact your health in different ways.

For a full understanding of each pollutant and what it means I recommend reading my article on understanding AQI. In it, I cover the different pollutants as well as the dangers and causes of each.

The CAI (Comprehensive Air Index) is used by the Ministry of Environment of South Korea and is the standard system used in the country. While it is very similar to many other AQI platforms, there is one key difference that many people will notice.

CAI Seoul Air pollution Colours

Namely, where many AQI scales start at green, the Korean CAI actually starts with the colour blue. Instead of green representing good air quality, it actually represents moderate air quality in Korea. This changes the whole colour-scheme, because now yellow represents unhealthy rather than moderate. This continues for the other colours.

Good Resources to Check Air Quality 

Plume Labs Air Quality App

I recently did a review of the best AQI apps.

I understand how bothersome it can be, however, it is worth checking the air quality every day. No matter how short you are going outside for. You can’t put a price on good health.

Luckily, there are a few great resources for checking the air quality in and around Seoul. Two great sites are Cleanair.Seoul and Air Korea. While both of these websites are in Korean, they are easy to understand. Simply look at the relevant district and check the colour.

Air quality colours will follow the traffic light. Green is considered safe, yellow can affect sensitive groups, orange is hazardous, red is dangerous, and purple/brown are highly dangerous. Luckily you will very rarely see purple and brown in Seoul.

The Seoul Government also provides a site for checking on air pollution. However, I’ve found the site to be quite limited in its readings compared to AQICN – I personally use AQICN because it monitors not only the AQI, but also every element that makes up the AQI.

However, there are also a lot of other apps and platforms that provide AQI readings. They provide not only a general rating on the air quality, but they also break down the different ozone and particle pollutants into categories. They also provide apps for IOS and Android.

Protecting Yourself from Seoul Air Pollution

South Korea Fine Dust Mask

While air pollution is something that should always be considered, it is also something that can be managed. It’s true that you can’t avoid air pollution, but you can minimise its impacts both inside and outside.

In this section I will cover methods to protect yourself both inside and outside. However, it is important to remember that these methods (especially masks) are limited and that they must be used correctly for the best protection.

Finally, while you may think that you are safe from air pollution inside, you are not. In fact, indoor air pollution is often worse than that which is found outdoors, and it’s important to make sure that you take steps to protect yourself indoors too.

When Do You Need a Fine-Dust Mask?

Respirator Ratings

Different sources have very different AQI levels listed as ‘safe’. The World Health Organisation states these as the guideline values for safe air:

Fine Particulate Matter (PM2.5): 10 μg/m3 annual mean, 25 μg/m3 24-hour mean.

Coarse Particulate Matter (PM10): 20 μg/m3 annual mean, 50 μg/m3 24-hour mean.⁹

These values are considered low in Korea, and it is rare for days to go below 35 μg/m³, let alone 10 μg/m³. Countries such as China only consider values above 200 μg/m³ unhealthy.

However, the WHO (World Health Organisation) does also admit that no level of fine dust pollution can really be considered ‘safe’. The only truly safe level of air pollution is zero.

It’s hard to identify an exact AQI rating that a mask should be worn at, especially since the WHO guidelines for long-term exposure are well below what Korea often experiences. The AQI site rates 0-50 as ‘healthy’ and that is what is generally believed.

I know many people who wear masks only when the air gets worse than 100(AQI) and some who wear at 150. For me, however, with asthma, anything over 75 begins to cause difficulty with breathing.

When you wear a mask is up to your discretion. The Chinese government recommends masks at 75μg/m³, the US government at 35μg/m³ and the WHO at 25μg/m³ (PM2.5). The issue is that air pollution affects you even at 1μg/m³, there is no clear definition of when it starts to become very dangerous.

If you want to stay as safe as possible then it is best to follow the WHO guidelines. Whenever PM2.5 exceeds 25μg/m³, don a mask. However, this level is very regularly exceeded in Seoul.

Purchase fine dust masks in Korea.

High-Risk Groups

Air Pollution Clean Air

If you fit any of the following groups you are more likely to be affected and will be more affected than others.¹⁰

  • People with lung diseases, such as asthma, chronic bronchitis, and emphysema, can be particularly sensitive to ozone. They will generally experience more serious health effects at lower levels. Ozone can aggravate their diseases, leading to increased medication use, doctor and emergency room visits, and hospital admissions.
  • Children, including teenagers, are at higher risk from ozone exposure because they often play outdoors in warmer weather when ozone levels are higher, they are more likely to have asthma (which may be aggravated by ozone exposure), and their lungs are still developing
  • Older adults may be more affected by ozone exposure, possibly because they are more likely to have pre-existing lung disease.
  • Active people of all ages who exercise or work vigorously outdoors are at increased risk.
  • Some healthy people are more sensitive to ozone. They may experience health effects at lower ozone levels than the average person even though they have none of the risk factors listed above. There may be a genetic basis for this increased sensitivity.

For more information on the health effects and information on other substances found in the air (such as carbon monoxide and sulfur dioxide), please refer to the Airnow website.

In the end, it is up to the individual to decide when a mask is required. There is no set level for masks, and everyone is affected differently. Following the guidelines of the table above however, it is recommended to wear a mask above an AQI rating of 100 if you are sensitive, and 150 otherwise.

Which Mask Should You Wear?

Cambridge Mask Design

I personally use the Cambridge reusable mask.

A common misconception is that buying any mask and wearing it will help protect your body from polluted air. This is NOT true. A recent study in China found that ‘Many commercially available face masks may not provide adequate protection, primarily due to poor facial fit. Our results indicate that further attention should be given to mask design and providing evidence-based guidance to consumers.’¹¹

There are many different masks available on the market and there are also many different rating systems. This can make picking the right mask very difficult. The good news though, is that finding the right mask might not be as hard as you think.

I have already written an in-depth post on the best fine dust masks in Korea, and I would recommend reading that if you want more details on the best masks to pick.

Generally, you will want to look for an N95, KF94 or equivalent respirator. These provide 94%+ filtration against fine dust particles and if worn correctly, they will provide at least some protection against fine dust.

If you are looking for a mask that can be reused, there are many on the market. Many of these masks either adhere to, or are qualified with different standards. The mask that I personally use is the Cambridge Mask. It provides 99% filtration (but it does NOT hold an NIOSH rating).

Some other masks that also provide fine dust filtration are the Idontcare Mask (92%), Vogmask (95%), Airinum (98%), and the Xiaomi Purely (95%).

Purchase fine dust masks in Korea.

Protect Yourself Indoors


Many people consider indoors to be safe, however, it isn’t. Simply closing the doors and windows is not enough to protect yourself from fine dust. Especially on days of high pollution, it is quite possible that even indoors you will be breathing particulate matter.

There are many devices that will allow you to monitor the air quality indoors. I recently reviewed the uHoo Air Quality Monitor and the Kaiterra Laser Egg. Both are great devices and I would recommend reading the full reviews if you want to take control of your indoor air quality.

However, even without knowing the quality of your indoor air you can take action and make sure that it remains clean. Make sure to open windows and have good ventilation, make sure to have some plants in your house, and if the air pollution is exceptionally bad, consider investing in an air purifier.

uHoo Air Pollution Monitor on Amazon

Best Air Purifiers

Indoor Air Pollution

If you are in Korea for the long term (longer than a year), an air purifier is definitely worth investing in. Not only will they clean your air of fine dust, but they will also clean it of many other pollutants and particles.

Two of the best air purifiers are the Alen Breathesmart and the Austin Air Healthmate Junior. However, both of these are quite costly. A great cheaper option is the Alen T500, and it is ideal for smaller apartments. Since most of the purifiers operate based on the size of the apartment, you are in luck! Korean housing is typically very small.

When purchasing an air purifier make sure that you purchase one that is capable of filtering PM2.5 particles. Secondly, make sure to purchase a purifier that is rated for the same (or a larger) size than your apartment.


Air Pollution Seoul

Fine particulate emissions have been on the decrease for years. However, the mortality rates associated with them are still climbing. The first steps have been taken to counter the lives taken by fine dust and air pollutants, however, the most important steps are yet to be taken. 

Whether or not the new Korean-Chinese artificial rain works, Korea also needs to focus more on domestic issues. While it is true that China contributes a significant amount of pollution, many reports point the finger at Korea as being the largest contributor. The best-case scenario is that both countries can work together to solve this very serious threat. 

My intention with this post was to help provide a more detailed insight into the air pollution crisis in South Korea, and Seoul. It can be hard to find information (especially in English) regarding the air and fine dust, and I hope that this post can help bring some more understanding to the situation and the causes, effects, and solutions of fine dust. 

If you noticed any inaccuracies in this post please email me at [email protected]. Further, if you have any more questions or comments feel free to either email me or leave a comment on this post. 


1. Muller, Richard A. and Elizabeth A. Air Pollution and Cigarette Equivalence.

2. Larson, Shannon. Time to see air pollution as a human rights threat: U.N. 5 March 2019.

3. Mostellar, Donald (2016). Air Pollution’s Hazy Future in South Korea.

4. Honghyok Kim, Hyomi  Kim, Jong-Tae Lee (2015). Effects of ambient air particles on mortality in Seoul: Have the effects changed over time?

5. Honghyok Kim, Hyomi  Kim, Jong-Tae Lee (2015). Effects of ambient air particles on mortality in Seoul: Have the effects changed over time?

6. Suehyung Lee (2018). Korea’s New Comprehensive Plan on Fine Dust and ItsImplications for Policy and Research.

7. Beverland, I. J., Cohen, G. R., Heal, M. R., Carder, M., Yap, C., Robertson, C., Hart, C. L., … Agius, R. M. (2012). A comparison of short-term and long-term air pollution exposure associations with mortality in two cohorts in Scotland. Environmental health perspectives120(9), 1280-

8. Pope III CA, Burnett RT, Thun MJ, et al. Lung Cancer, Cardiopulmonary Mortality, and Long-term Exposure to Fine Particulate Air Pollution. JAMA. 2002;287(9):1132–1141. doi:10.1001/jama.287.9.1132

9. World Health Organisation (2018). Ambient (outdoor) air quality and health.

10. U.S. EPA Office of Air Quality Planning and Standards (2014) Air Quality Index – A Guide to Air Quality and Your Health.

11. Cherrie, J. W., Apsley, A., Cowie, H., Steinle, S., Mueller, W., Lin, C., Horwell, C. J., Sleeuwenhoek, A., … Loh, M. (2018). Effectiveness of face masks used to protect Beijing residents against particulate air pollution. Occupational and environmental medicine75(6), 446-452.

Is Air Pollution Bad in Seoul?

Although not as bad as many cities around the world, air pollution in Seoul does pose a health risk. The air pollution in Seoul is often significantly above the standards set by the WHO.

Further, there are often a few very polluted days every year in Seoul. On these days, the air pollution is considered dangerous for everyone, and staying inside is recommended.

How Can I Check the Air Quality in Seoul?

Luckily, there are a few great resources for checking the air quality in and around Seoul. Two great sites are Cleanair.Seoul and Air Korea. While both of these websites are in Korean, they are easy to understand. Simply look at the relevant district and check the colour.

When Do You Need a Fine-Dust Mask?

It’s hard to identify an exact AQI rating that a mask should be worn at, especially since the WHO guidelines for long-term exposure are well below what Korea often experiences. The AQI site rates 0-50 as ‘healthy’ and that is what is generally believed.

I know many people who wear masks only when the air gets worse than 100(AQI) and some who wear at 150. For me, however, with asthma, anything over 75 begins to cause difficulty with breathing.

When you wear a mask is up to your discretion. The Chinese government recommends masks at 75μg/m³, the US government at 35μg/m³ and the WHO at 25μg/m³ (PM2.5). The issue is that air pollution affects you even at 1μg/m³, there is no clear definition of when it starts to become very dangerous.

When Is Fine Dust Season in Seoul?

If you hear the term ‘fine dust season’, then it is most likely referring to the months of January-May. During these months fine dust in Seoul is more severe due to dry weather and Yellow Dust.

Is Air Pollution in Seoul Dangerous?

Yes, it is dangerous. However, it isn’t something that you need to overly worry about. Managed well, you can minimise the dangers of air pollution.

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