traffic jam, transport

Every morning, as I walk to the subway to go to class, a couple old Route 54 buses would roll by, leaving behind a cloud of black exhaust  for me and everyone else to inhale. Each and every time, it leaves me wondering, “what could possibly be in the air we breathe everyday?”

Whether you walk, drive or commute, you will definitely notice the air quality, or lack thereof. We seem to be getting less and less clean air everyday, especially in Bangkok where many have probably forgotten how it is to breathe fresh air.

One of the most harmful substances in our atmosphere, as I've learned, is PM2.5-- particulate matter that is smaller than 2.5 micrometers. That’s a quarter of a diameter of a single strand of human hair, definitely smaller than what the naked eye can see. Now try to imagine how that tiny particle makes its way through your nostrils and into the lungs every time you step outside your home.  Just because you don’t see these tiny pollutants, doesn’t mean it will not affect you. In the long run, it can weaken one's immune system, damage the respiratory system which may lead to coughing, choking, having reduced lung capacity, and even blockage of oxygen to your vital organs. At worse, it can lead to cancer.

With the help of a friend, I embarked on a journey to find out how Bangkok people deal with the problem of air pollution.  Using a portable monitoring device provided by Greenpeace, we went around to measure PM2.5 present in various locations across the city.

According to the World Health Organization (WHO), air quality measurements are typically reported in terms of daily or annual mean concentrations of PM10 particles per cubic meter of air volume (m3).

We also referred to the Air Quality Index (AQI), a standard that countries follow as it corresponds to national standards. In Bangkok's case, we used guidelines set by the United States Environmental Protection Agency (USEPA) and by the China State Environmental Protection Administration (SEPA), as Thailand’s Pollution Control Department (PCD) has yet to incorporate PM2.5 into its AQI.

Using the USEPA, the AQI with values from 0-50 indicate good, 51-100 is moderate, 101-150 is unhealthy for sensitive groups, 151-200 is unhealthy, 201-300 is very unhealthy, and 301-500 is deemed hazardous. As for AQI based on SEPA, the values from 0-50 indicate excellent, 51-100 is good, 101-150 is slightly polluted, 151-200 is lightly polluted, 201-300 is moderately polluted, and anything over 300 means heavily polluted.


After conducting our little monitoring exercise, what we found was not good news.

Air quality at a green space like Lumpini Park seemed healthy at USEPA AQI = 25/SEPA AQI = 6, air from other places was not as pleasant. And while the air inside a BTS skytrain was USEPA = 50/SEPA AQI = 12, air from the air-conditioned Terminal 21 mall was poorer at USEPA AQI = 63/SEPA AQI = 27. It was as bad as the open-air corridors of Siam Square, with AQI USEPA AQI = 73/SEPA AQI = 35. Even on the 14th floor of a building in the Chulalongkorn campus, USEPA AQI = 63/SEPA AQI = 22 was measured. In fact, being in any of these three locations could be as bad as standing by the road intersection at Asok, which measured USEPA AQI = 63/SEPA AQI = 24.


“The air at Pratunam is worse, it stings my nose,” says Kajornsuk Suebsuk, a motorcycle taxi driver around Siam Square.

Although we had already braced ourselves for bigger numbers in areas with visible smog, we were not prepared for the results at Hua Chang Pier. Though our device indicated pollution at USEPA AQI = 185/SEPA AQI = 85 and PM2.5 of 70 μg/m3 at times the klong was clear, it peaked with USEPA AQI = 449/SEPA AQI = 500 and PM2.5 to 420 μg/m3 when a passenger boat came by and left behind a trail of black exhaust.


“I think if I had to walk, I’d rather walk by the klong because the wind is much better. The road looks and feels more cramped-- with the smell, noise,” said Adul Gornjan, a boat service staff at Klong Saen Saep. It is scary to think, that a huge fraction of Bangkok’s population use these boats for their daily commute, and many seem unaware of the dangers they face everyday.

Here comes the most shocking part. At the well-known Erawan Shrine, popular among both locals and tourists, values on the device maxed out at USEPA/SEPA AQI = 500 due to smoke from incense and candles. PM2.5 was measured at a choking 674 μg/m3 and even reached 900 at one point. Now that is deadly.


All the results mentioned were part of fluctuating values observed at each location, taken between late in the morning and afternoon of a single day, following heavy rainfall from the previous night. Usually, accurate data on air quality requires averaging measurements of not only pollutants, but also several other factors and conditions throughout a specific period--including time, time span, frequency, temperature, weather, wind speed and direction, location, human bias and errors, and equipment calibration-- all need to be considered so as to ensure information that best represents the overall AQI. For this reason, the Pollution Control Department's expertise and resources play a crucial role in the well-being of all Thais.

“What the government could do is enforce more and stricter regulations to limit the use of resources that would contribute to pollution. Sometimes encouragement campaigns don’t work because Thais like to break rules,” says Adiruj Punja, a skytrain passenger, who believes Bangkok’s current air quality “damages his mental health”.

With over 61 monitoring stations set across 29 provinces in Thailand, only 14 of those stations in 14 provinces are installed with PM2.5 monitors. Already eight of these monitors show annual averages that exceed Thai AQI guidelines, which is 25 μg/m3 or 2.5 times higher than that of WHO.

PM2.5 is emitted from a wide range of human activities from fuel combustion from vehicles, power plants, and industrial processes, to cooking, smoking, burning trash, and chemical reactions in the atmosphere. The pollution can remain in the atmosphere for a prolonged period of time, regardless of its chemical composition-- think mercury, cadmium, arsenic, and polycyclic aromatic hydrocarbons (PAHs). Furthermore, these particles are known to be formed in or travel far from its original source. Now we know that what happens in Bangkok, doesn’t stay in Bangkok.

As part of the air pollution that kills 6.5 million people around the world annually, these pollutants pose an extremely serious threat to human health on a global scale. This reason alone should be enough to justify the need for the PCD to install PM2.5 monitors in all stations across Thailand, as well as upgrade the country’s AQI to incorporate the pollutant

By doing so, the PCD would not only provide Thais with proper and complete information on air quality, but also enable them to effectively protect themselves from air pollution. Furthermore, the reports would serve not only the purpose creating of public awareness, but can also act as a standard which PM2.5 producers can use to reduce their emissions based on the given assessments and guidelines.

While individuals now have access to ways to measure air quality as a result of present-day technological advances, it should be the responsibility of governments to provide its citizens with information on the living standards that the country offers. After all, we have the right to know what we breathe, and most importantly, the right to clean air.


Nanticha Ocharoenchai is a student and an aspiring journalist. She volunteers for Greenpeace Thailand and hopes to contribute to a better world through her stories on the environment.