Air quality in Yala

How polluted is the air in Yala?

Yala is a city in southern Thailand that finds itself very close to the border with Malaysia. With a distance of approximately 1,100km from the capital city of Bangkok, Yala has a small population of just over 60 thousand people. Pollution levels remain quite stable throughout the year, with some discrepancies from other cities in Thailand. This could be that whilst it has quite a decent yearly average, it does not see the extra clean air quality months that other cities in Thailand often see, even if their yearly average is worse than Yala’s.

In 2019, Yala came in with a PM2.5 reading of 20.9 μg/m³, putting it into the ‘moderately’ polluted bracket. In order to achieve this rating, a city must have an average PM2.5 reading anywhere between 12.1 to 35.4 μg/m³ to be classified as moderate. This shows that whilst Yala does not suffer from disastrous levels of pollution, it could certainly stand to lower its levels if it were to come closer to achieving the World Health Organizations target goal of 0 to 10 μg/m³ of fine particulate matter in the air, a feat that could be achieved if Yala were to slash its reading by more than half.

This 2019 reading of 20.9 μg/m³ put it in 54^th place out of all cities ranked in Thailand, and 836^th position out of all cities ranked worldwide. In more recent times, in the latter part of 2020 there are PM2.5 readings that are steadily fluctuating between ‘moderate’ pollution levels and ‘good’ pollution levels, with the good rating requiring a reading of 10 to 12 μg/m³.

What are the main causes of pollution in Yala?

As with many cities there are several main causes of pollution, some of them being more ‘ambient’ forms of pollution such as car exhaust and factory smoke emissions, which carry on throughout the year and raise the overall levels of pollution and PM2.5 in a consistent manner. There are other sources that are more acute in their nature, such as forest fires from neighboring countries, in particular Indonesia and its island region of Sumatra.

This causes vast amounts of haze and smog to be blown over, where it can get stuck in the atmosphere of many cities located throughout Thailand and Malaysia, failing to disperse due to the urban topography, with tall buildings and lower levels of elevation (as well as other factors such as weather e.g., windspeed or humidity levels) all causing these noxious fumes to build up and cause harmful spikes of pollution to occur. This seems to be the most prominent issue in Yala, due to its close proximity to Malaysia, which is known to suffer terribly in the month of September due to these forest fires.

As previously mentioned, the other sources besides trans-border smoke issues include the over use of cars (particularly ones running on diesel) as well as fume emissions from industrial areas such as factories or construction sites.

When did Yala see its worst levels of pollution?

Referring to the levels of PM2.5 recorded over 2019 (with PM2.5 being fine particulate matter that is 2.5 micrometers or less in diameter), the month that saw the highest concentration of pollution was September, coming in with a reading of 36.7 μg/m³, significantly higher than the rest of the year and the only month to be sitting in the ‘unhealthy for sensitive groups’ bracket.

This is of course due to the smoke and haze being blown over from Sumatra, where farmers still practice the highly illegal slash and burn farming practices, whereby vast swathes of forest and farm land are set ablaze in order to clear crop stubble and return nutrients to the soil.

Whilst this may have been an acceptable and practical method of farming in the past, due to the massive increase in product demand as well as population booms occurring, the number and size of these fires have simply become too large, causing catastrophic consequences for the southern part of Thailand, Malaysia as well as Singapore.

Other months of note were January, March, April, July and August, all of which came in with readings over 20 μg/m³, making them somewhat more polluted yet nowhere near as bad as September. The cleanest month of the year in 2019 was May, with a reading of 14.7 μg/m³, placing it only a few units away from the ‘good’ rating bracket.

Are pollution levels in Yala improving?

Looking back at the averages recorded over the last few years, it appears that the air quality in Yala is actually getting slightly worse instead of improving. 2017 came in with a yearly average of 17 μg/m³, followed by a reading of 19 μg/m³ in 2018. This was raised even further in 2019, with the aforementioned reading of 20.9 μg/m³, showing that the levels of PM2.5 are slowly increasing by several units each year.

Whilst this is not a cause for major concern when looking at the numbers, it stands to reason that Yala could certainly implement more strategies to improve the quality of its air over the coming years. Of note is that the month of September does massively skew the yearly average, something that is out of the hands of Thai governing bodies and as such is not the fault of the citizens of Yala.

What kind of pollutants would you find in the air in Yala?

To name but a few of the many noxious compounds and fine particulate matters found in the air, it would include ones from varying sources. Cars and factories give off larger amounts of compounds such as nitrogen dioxide (NO₂) and sulfur dioxide (SO₂), with nitrogen dioxide being the leading offender in vehicular emissions, often found in high concentrations in any area that sees larger amounts of traffic.

The burning of vast areas of forestland and organic matter would lead to large amounts of particle matter such as black carbon and volatile organic compounds being released. Black carbon is a major component in soot, and is also found in the emissions of vehicles that run on fossil fuels. Both are formed from the incomplete combustion of fossil fuels as well as the burning of wood and other organic materials. Other toxic compounds released from organic matter would include benzene, carbon monoxide (CO) and polynuclear aromatic hydrocarbons, all of which can have a plethora of detrimental effects on those who breathe them.