Air quality in Samut Prakan

How bad is the air pollution in Samut Prakan?

Samut Prakan is a city in Thailand within the metropolitan district of Bangkok, giving it a close proximity to the capital. It also has a coastal location, with part of the city facing onto the gulf of Thailand. As with many cities in Asia, it faces fluctuating levels of pollution that can differ vastly month by month, with reasons mostly related to topography, weather and human activity.

In terms of statistics, Samut Prakan came in with a PM2.5 reading of 22.9 μg/m³ in 2019, ranking it at 727^th place in terms of all cities worldwide. PM2.5 refers to fine particulate matter that is 2.5 micrometers or less in diameter, or roughly 3% the size of a human hair. Due to this microscopic size, it is a major component it calculating the overall level of air pollution, due to its highly detrimental effect on human health when inhaled.

Returning back to the reading, 22.9 μg/m³ would place Samut Prakan into the ‘moderate’ pollution bracket for the year of 2019, a rating that requires a PM2.5 reading of any number between 12.1 to 35.4 to be classified as such. This also placed it into 47^th place out of all Thai cities ranked in 2019, just one position ahead of its close neighbor Bangkok, which came in at 48^th place with a PM2.5 reading of 22.8 μg/m³, just 0.1 μg/m³ shy of matching each other.

Whilst there are several differences between the readings of the two cities, with some months being vastly different, due to their close proximity they would suffer from many of the same pollution problems. As such, Samut Prakan is not subject to the terrible levels of pollution that some cities in Asia might see, with some months coming in with a good quality of air, but it still has months that tarnish its overall pollution levels and make its air potentially hazardous to breathe.

What are the main causes of air pollution in Samut Prakan?

Much like any city that finds itself part of the metropolitan district of Bangkok, pollutive issues would range from ones such as industrial smoke, vehicular emissions and other human related activity such as the burning of waste materials or organic matter, as is seen practiced in slash and burn farming.

Although this is less prevalent nowadays due to being highly illegal, it can still occur in some provincial areas outside of major cities and cause vast swathes of haze and smog to be blown in and trapped over urban areas, with events such as this occurring early in 2019 and causing high levels of pollution in Bangkok to occur, due to the gathering of smoke and haze which was unable to disperse due to being trapped within the confines of hundreds of tall buildings. In closing, the main sources of air pollution in Samut Prakan come from vehicles, the industrial sector as well as open air burning.

What type of pollutants would be found in the air in Samut Prakan?

With its three main causes of pollution all being identified, the main chemicals and fine particulate matter that would stem from these sources would be prominent ones such as nitrogen dioxide (NO₂) and sulfur dioxide (SO₂), both of which see release from car engines, not to mention the vast amount of motorbikes, rickshaws, boats and trucks that make their way in and out of the many roads of Samut Prakan and its neighboring cities, as well as the many waterways that also snake around Bangkok and its many districts, providing travel for locals as well as tourists.

Nitrogen dioxide is always the main offender in areas that see high vehicle use, often gathering in such a way that high readings of this secondary pollutant are strong indicators that the area is subject to excessive amounts of traffic.

Other pollutants would include ones that come from open burn sources, such as carbon monoxide (CO), benzene, volatile organic compounds (VOC’s), polynuclear aromatic hydrocarbons, as well as black carbon. VOC’s and black carbon are both released when fossil fuels are burnt, and as such would find themselves being emitted from any motor that runs on diesel fuel. This is still quite prevalent in Thailand, causing large amounts of these dangerous particulate matters and gases to make their way into the atmosphere.

Is the air pollution level improving in Samut Prakan?

Based off of the numbers taken over the last few years, it shows the Samut Prakan is experiencing a gradual increase in the cleanliness of its air quality, with a fairly prominent leap recorded between the averages of 2018 and 2019.

2017 came in with an average PM2.5 reading of 33.2 μg/m³, placing it at the higher end of the moderate pollution rating and fairly close to moving up a bracket to the ‘unhealthy for sensitive groups’ rating, which requires a reading of 35.5 to 55.4 μg/m³ to be classed as such.

2018 saw a very slight improvement, with an average of 32.2 μg/m³, an improvement of only 1 μg/m³. However, signs of improvement were indeed shown as in 2019, the levels of PM2.5 came in at 22.9 μg/m³, an improvement of nearly 10 μg/m³.

This does indicate a good level of improvement, although readings taken in the latter part of 2020 are showing large fluctuations between their ratings (jumping between ‘good’ classifications up to the ‘unhealthy for sensitive groups’ rating). With some strong emphasis on pollution improvement and similar initiatives, the city of Samut Prakan may be able to push its numbers down and get close to the World Health Organization's target goal of 0 to 10 μg/m³.

When is pollution in Samut Prakan at its worst?

When reviewing the year of 2019, one month stands out as having extraordinarily high readings of PM2.5. January came in with a reading of 60 μg/m³, putting this month into the ‘unhealthy’ bracket, which means that the whole of the population would be at risk when breathing its air over extended periods of time.

Other months of note were December, with a reading of 37.7 μg/m³. This indicates that pollution levels will generally get worse towards the end of the year, and subsequently see a peak in January. The months that were recorded as having the cleanest air quality were June through to August, with August being the only month of the year to fall under 10 μg/m³ and achieve the WHO’s target, with a reading of 8.9 μg/m³ in terms of fine particulate matter pollution in the air.