Qualité de l’air à Khon Kaen

How bad is the level of air pollution in Khon Kaen?

Khon Kaen is a city in the mid northeastern region of Thailand, some 450km away from the capital city of Bangkok. It belongs to one of the four major cities of northeast Thailand, also known as Isan. The other three major cities of this region are Udon Thani, Nakhon Ratchasima and Ubon Ratchathani. There are approximately 114 thousand people living in Khon Kaen as of 2019.

Pollution levels in Khon Kaen are something that is of quite significant concern to its citizens, with levels of pollution coming in fairly high in terms of fine particulate matter (PM2.5) found in the air, along with a poor US AQI or air quality index rating. US AQI is a measurement used to rate the cleanliness of the air, along with the PM2.5 count also being a good indicator to go by when measuring the amounts of fine particulate pollution in the air. Khon Kaen came in over 2019 with a PM2.5 reading of 36.4 µg/m³, putting it in position number 8 out of all the most polluted cities in Thailand.

This reading of 36.4 µg/m³ would put it into the ‘unhealthy for sensitive groups bracket’, which requires a reading of PM2.5 anywhere between 35.5 to 55.4 µg/m³ to be classed as such. This is a poor yearly average, coming in way ahead of the capital city of Bangkok in terms of how polluted it is. That should give some perspective in terms of its pollution problems, due to Bangkok itself being famous for its high levels of pollution as well as the thick haze and smog that can permeate the sky for many months of the year, with spells of smoke that have been so bad that schools have been forced to close as well as transport and other day to day activities being significantly hampered. For contrast by numbers, Bangkok came in with a PM2.5 reading of 22.8 µg/m³ in the year of 2019, putting it in 48^th place out of all ranked cities in Thailand (68 in total).

Khon Kaen was one out of eight cities in Thailand to come in with the unhealthy for sensitive groups rating, and if the other months out of the year are to be observed, that are certainly some higher pollution levels coming in. Two months out of the year (2019) came in in the ‘unhealthy’ bracket. This is not just a description of how bad the air quality is but also a numbered ranking, requiring a PM2.5 reading of anywhere between 55.5 to 150.4 µg/m³ to be classed as unhealthy. This is certainly an undesirable reading to be given, with a whole host of health problems, both short and long term to take into consideration for those who are breathing its air. From May through to November its pollution ratings were ‘moderate’ (12.1 to 35.4 µg/m³), making the majority of its year come in with a moderate rating. However, during its worst months, pollution levels climbed high enough to tarnish the year and give it its poorer rating, making the air quality in Khon Kaen of concern for those breathing it.

What are the main causes of pollution in Khon Kaen?

As is typical to much of Thailand, especially the cities in certain regions that suffer from heightened levels of pollution, Khon Kaen finds its pollutive issues coming from similar sources. Vehicles are the eternal and main offender in the climbing levels of pollution, usually coming in at the top spot for many cities around the world, not just endemic to Thailand or indeed south east Asia.

When taking into consideration pollution coming from vehicles, it can be observed that there are many other compounding factors, such as the quantity of vehicles in any given area (vehicular concentration) as well as the fuels they are running on. Although there is a continued clamp down on the use of fossil fuels and in particular diesel, it still stands that there are many vehicles (particular trucks and motorbikes) that flood the road that are still running on diesel fuels.

This fossil fuel releases a larger amount of pollution into the atmosphere than its cleaner counterparts, with chemicals and both primary and secondary* pollutants being released as a result. Of particular importance are compounds such as nitrogen dioxide (NO₂) and sulfur dioxide (SO­₂), with nitrogen dioxide being the main emission from diesel-based fumes. Large concentrations of this are often found in areas that see a high level of traffic, with such a high correlation rate available that one could actually infer the amount of vehicular movement in any given area by the amount of nitrogen dioxide found in the atmosphere, and the same would apply to the other way round (with some variations due to geographical or environmental factors such as wind speed, elevation and temperature/humidity levels.

Sulfur dioxide can be found in areas that have a high number of refineries and power plants, being one of the main (amongst many) pollutants released from the burning of fossil fuels. It can also be released by trains and heavy machinery. Industrial sites are numerous around Khon Kaen, with concrete and other industrial appliance factories finding themselves spread across the city.

Besides the pollution caused by vehicles and industrial areas, there is an issue of crop stubble burning, as well as other organic materials being set ablaze, both by human action and also occurring naturally (forest fires and the like). This would fall under pollution caused by the agricultural sector, especially when referring to the burning of fields and plantation areas. Despite the practice being heavily outlawed, it still continues to occur every year due to the difficulty in enforcing it, with sugarcane and rice fields being the main crops that are being burnt. This would release a large amount of smoke, haze and other contaminants into the atmosphere, whereby they can combine with the pollution emitted by vehicles and factories to create even more dangerous forms of fine particulate matter.

Referring back to the previously mentioned primary and secondary* pollutants, to get a better understanding of this and how pertains to pollutants and air quality in Khon Kaen, a primary pollutant is one that is released directly from the source, such as the exhaust fumes from a car and burning of organic materials, as well as construction sites and factory emissions. These would include heavy metals such as lead or mercury particles, as well as volatile organic compounds (VOC’s) and carbon monoxide (CO).

A secondary pollutant would be one that is formed from a combination of primary pollutants, including compounds such as ozone (O₃), sulfuric and nitic acid, which are the main contributors of acid rain, and nitrogen dioxide. Of note is that some pollutants can be both primary and secondary, such as the aforementioned nitrogen dioxide. It can be formed directly from vehicle exhaust fumes, and can also be formed later on via chemical reactions taking place in the atmosphere. To finish, the three most pertinent sources of pollution in Khon Kaen are fumes from vehicles, smoke and haze from the burning of organic matter, as well as industrial emissions from the various factories found within the city.

What are some health issues that arise from breathing the air in Khon Kaen?

Due to Khon Kaen’s poorer quality of air, there would be higher incidence of its citizens suffering from the negative health effects that arise from breathing polluted air. Amongst some of these effects would be ailments such as irritation to the eyes, nose, mouth and respiratory tract, and a higher rate of cancer, particularly that of the lungs. PM10 can cause these to occur as well as inducing chest infections and triggering off asthma attacks in certain individuals. On a more dangerous scale and due to its incredibly small size, PM2.5 can make its way deep into the lung tissue when inhaled, causing chronic obstructive pulmonary disease’s such as bronchitis and emphysema. If young children are exposed during their critical developmental stages, side effects can include permanently reduced lung function, growth defects as well as cognitive impairments. For mothers who are carrying unborn babies, the possibility of them being born with a birth defect is also increased. To look at a particularly bad month in Khon Kaen, such as March 2019 that came in with a reading of 68.6 µg/m³, prolonged exposure to breathing such polluted air does carry the very real risk of suffering from the previously mentioned illnesses and conditions.

Besides respiratory conditions, cardiovascular issues can also arise due to the incredibly small size of PM2.5. it can travel from the lungs via the bloodstream to the heart and cause damage to the blood vessels, heart diseases and increased rates of cardiac arrest occurring.

When is Khon Kaen at its most polluted?

Going once again off data taken in 2019, the months that had the worst pollution in Khon Kaen were February and March, with respective readings of 67.2 and 68.6 µg/m³, both very high and in the ‘unhealthy’ bracket. This follows a similar trend with Thailand, with other more polluted months being January, April and December, all coming in with ‘unhealthy for sensitive groups’ readings. This goes to show that the first few months and end of the year are when Khon Kaen is suffering from its worth levels of pollution, with March coming in at the highest out of all of them.

What can you do to prevent the negative health effects of breathing the air in Khon Kaen?

In order to negate the negative health effects of living in or travelling to a polluted city such as Khon Kaen, one can take preventative measures such as the wearing of high-quality particle filtering masks, as available on the IQAIR website. Other actions that would be of help would be staying up to date on pollution levels via air quality maps, also found on site, as well as being available on the AirVisual app. These give daily and hourly readings of pollution in any given area, and as such decisions can be made based off of PM2.5 readings. If a day is particularly bad, measures such as staying indoors, avoiding outdoor exercise or activity or using air purifiers at home would all go a long way in preventing these negative health effects from arising.