清萊的空气质量

Does Chiang Rai have a good air quality rating?

Chiang Rai is a major city in Thailand located at the northernmost part of the country, with a population of some 200,000 or more people. It spans an area of some 61 km2, a city of modest size in comparison to Bangkok’s 1,569 km². Going by measurements taken over 2019, Chiang Rai had an average PM2.5 rating of 37μg/m3, in regards to the content of fine particulate matter recorded in the air.

This reading of 37 μg/m3 puts it into ‘unhealthy for sensitive individuals’ bracket, which requires a reading somewhere between 35.5 to 55.4 μg/m3 of PM2.5 in the air to find itself in this group. This is considerably further over the World Health Organizations target of 0 to 10 μg/m3, or even a ‘good’ rating of 10 to 12 μg/m3. Furthermore, the reading places it number 5 in the list of the 50 cities ranked in Thailand, a considerably high ranking when you consider that Bangkok, world renowned for its pollution choked roads, smoke and haze, is only ranked at number 48.

Chiang Rai saw its worst readings regarding the PM2.5 during the months of March through till May, with all three of those months coming in at the ‘unhealthy’ bracket, with March being the worst offender with a PM2.5 rating of 113.8 μg/m3, a number indicating that the air would be full of noxious pollutants such as nitrogen dioxide (NO2), Sulphur dioxide (SO2) as well as numerous volatile organic compounds (VOC’s), the origins and causes of which will be discussed later on. However, as with most cities in Thailand, it has its brief respite during monsoon season when the air quality drops to within the WHO’s target of 10 μg/m3 or less, with June coming in at 10.4 μg/m3 (a ranking that puts it in the ‘good’ bracket), then July and August coming in at 7.6 and 7.2 respectively on the air quality index.

What are the main causes of pollution in Chiang Rai?

The main causes of pollution in Chiang Rai are a similar story told throughout Thailand, and other countries in the region. Besides the smoke and other contaminants containing PM2.5 given out by vehicular emission, slash and burn farming is the culprit which causes the massive spikes in the air quality index and the levels of PM2.5 to rise so high. These practices produce vast amounts of the aforementioned VOC’s, along with black carbon (BC), an extremely dangerous form of PM2.5 that has not only prominent health effects on people, both long and short term, but impacts the atmosphere, contributing to global warming and climate change.

Despite warnings of retribution by governing bodies and international pressure, these practices continue to take place year after year unabated. The farmers resort to slash and burn methods, whereby they set fire to vast swathes of both forests and farmland in preparation for their crop plantation preceding the rainy season. These practices would start around March, a prime indicator for the sizeable increase in the PM2.5 levels recorded in the data charts, with a PM2.5 reading of 40.5 μg/m3 recorded in February jumping up to 113.8 μg/m3 in March.

Besides this, the other causes would be the usual smoke and haze emission from factories and other industrial sectors. Chiang Rai is also home to a large collection of temples and other cultural attractions, as well as beautiful jungle and mountain landscapes that would be a driving factor for growth in the tourism sector. This would increase pollution from vehicular emission from the numerous buses and cars coming in and out of Chiang Rai, although this industry will have been slowed considerably in 2020 due to the COVID-19 outbreak.

What effect does the quality of the air in Chiang Rai have on health?

The effects of PM2.5 as well as its larger cousin PM10, particulate matter of 10 or less micrometers across, can have numerous negative effects on our health. The smoke and haze released from the burning of organic materials can trigger asthma attacks in people with preexisting conditions, worsening symptoms of chronic obstructive pulmonary disease (COPD) or being a root cause of them in the first place, with prolonged exposure to both PM2.5 and PM10 reducing life expectancy, increasing the risk of cardiovascular issues and decreased lung function.

During the worst months of the year when the haze pollution starts to permeate the atmosphere, winds can bring about vast amounts of the carcinogenic dust into contact with the city’s population.

To go into further detail about the risks that poor air quality can pose to health, short term effects from exposure to smoke and pollution containing both PM2.5 and PM10 can include ailments such as pneumonia or bronchitis, as well as irritation to the respiratory tract (both internal and external) and irritation to the skin. Longer term effects can cause permanent reduction to lung function or emphysema (part of COPD’s symptoms), as well as heart disease and various forms of cancer, tending mainly towards lung cancer. Due to the extremely small particle size of PM2.5, it can find its way into the bloodstream and travel to many parts of the body where it will accumulate over the years, causing a wide variety of carcinogenic effects.

With such things considered, awareness of the air quality at certain times of the year would certainly be of great benefit, with apps such as AirVisual providing constant AQI readings to stay informed on the level of pollution. Avoiding outdoor activities on particularly bad days or the wearing of masks would be an action of significant importance.

What is being done about the levels of pollution in Chiang Rai?

Despite the aforementioned threats of arrest or other legal consequences against those involved in the smoke and haze caused by forest fires, little seems to have improved. 2019 seems to have been a turning point in the involvement of authorities after a particularly bad spell of smoke and haze. It was so severe that it caused schools to be shut down in Bangkok, as the haze failed to disperse even after several weeks.

The ministry of natural resources and environment conducted meetings during 2019 to discuss what actions could be taken to address the issues, whilst a branch of the government responsible for ‘rain seeding’ (whereby rain clouds are created artificially in order to cleanse the air) deemed the situation to be of a serious enough nature that this technology be applied to it. Once again these are only temporary measures that do little to address the root cause of the problem, just providing a transient fix to an issue that simply put, needs full intervention to those causing the forest fires.

How polluted is Chiang Rai when compared with another city?

When compared to a neighboring city such as Chiang Mai, IQAir’s world air quality reports indicate that Chiang Mai had an overall better quality of air in 2019, with a yearly average of 32.3 μg/m3, putting it into the ‘moderate’ air quality grouping, as opposed to Chiang Rai’s 37 μg/m3 that places it in the ‘unhealthy for sensitive groups’ bracket. Chiang Mai had three months where the recorded levels of PM2.5 in the air met the WHO’s target, as opposed to Chiang Rai’s two months.

With this considered, it cannot be ignored that Chiang Mai also suffered from a terrible air quality rating during the month of March, with a PM2.5 reading of 98.7μg/m3, not far off from Chiang Rai’s 113.8μg/m3 during the same time period. However, despite similarities and some months that were subject to similar levels of pollution, Chiang Mai still comes in at a ranking of 16th place out of the 50 cities’ in Thailand, much further off than the 5th place ranking of Chiang Rai, making it a more optimal place to live if the quality of the air is of concern.