Air quality in San Sai

What is the air quality level like in San Sai?

The air quality in San Sai is an ongoing topic of contention, much like many cities and regions located in the northern region of Thailand. This is due to one main reason, that will be mentioned in short, as well as other common causes of pollution, more responsible for raising the ambient US AQI and PM2.5 readings in the air. looking at some of the levels of pollution taken in San Sai, it can be seen that a US AQI reading of 85 was present in late May of 2021.

This reading of 85 placed it in the ‘moderate’ pollution ratings bracket, which falls into the acceptable category of air quality as per the standards of the US Environmental Protection Agency (US EPA), which ranks AQI readings from 0 up to 150 as being acceptable, and anything above that as starting to fall into a rapidly deteriorating and dangerous category.

These are color coded for ease of use and navigation, with ‘good’ air quality readings being green and requiring a US AQI reading between 0 to 50, ‘moderate’ being yellow and requiring 51 to 100, and ‘unhealthy for sensitive groups’ being orange and requiring a reading of 101 to 150. Of note is that whilst this last grouping is still considered acceptable, it may still present many health risks to both the general public as well as the mentioned at-risk or vulnerable portions of the population.

With San Sai presenting its reading of 85 in May, at this time, the air would still have a fair amount of smoke, haze and fine particles floating around in the atmosphere. Other readings on record prior to the one mentioned above were US AQI readings of 94, in the upper reaches of the moderate pollution bracket, as well as readings of 110 and 135, both of which were rated as being unhealthy for sensitive groups. A high of 153 was also taken in late April, indicating an ‘unhealthy’ level of air quality for that particular day in which it was taken.

Of note is that the northern region of Thailand is subject to its infamous ‘burning season’, with the early months of the year having some severe levels of air pollution, which will be demonstrated by their PM2.5 levels on record over the course of 2020, mentioned in the following question. On days where the US AQI reading comes in as unhealthy, a majority of the population may be subject to a number of health issues, particularly if pollution exposure is excessive, or maintained for a long period of time (which may be the case for those who live in areas that have a constant source of ambient air pollution, such as near busy roads and highways, as well as industrial areas).

What health risks come from breathing polluted air in San Sai?

A number of health risks can present themselves amongst all members of the population, with the aforementioned at-risk groups being even more vulnerable for a variety of reasons. People who fall under this category are ones such as the elderly and infirm, who are highly susceptible to the damaging effects of respiratory or cardiac conditions, with simple or superficial illnesses sometimes having more grave or terminal consequences, particularly if they lead a sedentary lifestyle or have other habits such as smoking.

Others include young children and babies, along with pregnant mothers, and those with compromised immune systems due to pre-existing health conditions, with the two often compounding each other. These groups may want to take extra care during spells of high pollution, resorting to preventative measures such as avoiding outdoor exercise and activity, along with wearing fine particle filtering masks when needed.

Regarding the main causes of air pollution in San Sai that may call for these situations, they are predominantly ones such as vehicle fumes and emissions (with a number of cars and motorbikes being of particularly poor or aged quality, thus leaking far more noxious gases and oil vapors), along with emissions from factories and power plants contributing to the release of many fine particles and chemical pollutants.

The most prevalent cause of air pollution, as touched on briefly before, is from fires started in rural areas and forest land, often used to clear said forested areas as well as on farms to return nutrients to the soil as well as clearing leftover crop stubble from previous harvests. This can cause severe elevations in the pollution levels, and due to the difficulty even in more modern times of cracking down on the practice, it continues to go on unabated, despite being classed as highly illegal. This is the main cause that is responsible for severe hikes in PM2.5 levels in the early months of the year.

At what times of the year is San Sai at its most polluted?

Observing the PM2.5 count as collected over the course of 2020, it can be seen that San Sai had its highest readings in the months of January through to April. They all presented with readings of 46.8 μg/m³, 73.5 μg/m³, 102.8 μg/m³ and 69.8 μg/m³ respectively, making March the most polluted month of the year by a significant measure with its reading of 102.8 μg/m³, over ten times the world health organization's (WHO's) target goal of 10 μg/m³ or less for the best quality of air.

When does the air quality in San Sai reach safer levels?

After the pollution levels from the ensuing fires start to subside, the months of June through to November all showed the best readings of PM2.5. June through to August all fell within the WHO's target goal with readings of 7.1 μg/m³, 7 μg/m³ and 9.7 μg/m³, making June and July the cleanest months of the year, with September and October following closely behind at 12 μg/m³ and 10.9 μg/m³, both falling into the ‘good’ air quality ratings bracket (10 to 12 μg/m³ required).

What are the most noteworthy forms of pollution in San Sai?

The various pollutants in the air in San Sai would be ones such as black carbon, the main form of soot and a byproduct of the poor or incomplete combustion of fossil fuels and organic material (such as dead plants or firewood). Volatile organic compounds (VOCs) also arise in a similar fashion from such sources, with chemicals such as benzene, toluene, xylene and tetrachloroethylene all falling under the VOC collective. Others include the pollutants that go into forming the US AQI aggregate reading, which are ones such as nitrogen dioxide (NO₂), sulfur dioxide (SO₂) and ozone (O₃).