Qualité de l’air à Nan

Is the air quality very bad in Nan?

The air pollution levels in Nan have shown quite high figures as of early 2022, with many days in January coming in with 'moderate' air pollution readings on the US AQI scale, then rising further to a large column of 'unhealthy' air quality ratings throughout a majority of February, indicating high levels of air pollutants present in Nan. In the early days of March 2022, Nan also was experiencing even higher air pollution levels, with US AQI readings of 168 coming in, placing it once again within the 'unhealthy' rating bracket, with a corresponding PM2.5 concentration of 88 µg/m³, a dangerous level that is nearly 18 times over the World Health Organization's (WHO's) safe exposure recommendations. As such, during this time of the year (and likely to continue for several more months), Nan is indeed polluted and great caution should be practiced to reduce the amount of pollution-related illnesses that can crop up amongst citizens.

When are the pollution levels higher in Nan?

Based on patterns observed throughout the country, recorded year after year, it is most likely that Nan will see its highest levels of air pollution at the same time that many other cities, towns and provinces in Thailand also see them, with larger amounts of smoke, haze and hazardous ultrafine particles permeating the air to a more dangerous extent during such months. Due to the countrywide issue of slash and burn farming practices, many of the air pollution readings throughout Thailand tend to follow the seasonal burning, with some cities in closer proximity to these practices following them almost directly, with higher pollution levels appearing as soon as the burning starts to take place, and abating around the time that it comes to an end, although residual clouds of smoke and haze can cause prolonged elevations in the US AQI and PM2.5 (and PM10) count. Furthermore, adverse weather conditions such as a lack of rain (which aids in removing some of the larger particles from the air by tamping them down, but has shown to not have a significant effect on ultrafine particles and any polluting gases that may be in the air) as well as lack of wind also playing a role in how long the pollution levels stay elevated. This remains true for pollution caused both by open burning as well as the myriad of other polluting sources. Wind remains as one of the most effective removers of air pollutants, with strong winds rapidly removing large amounts of hazardous accumulations (albeit not removing it entirely as they can be blown over to nearby towns and cities, although the overall dispersal of gases and particles can serve to lessen their ill effects).

With all these facts noted, as well as the pertinent point of deviations from the norm always being possible (another case as to why pollution levels should be carefully monitored, with forecasts being available both on this page as well as the AirVisual app), it remains that Nan and indeed many areas throughout Thailand tend to see heightened levels of pollution crop up in the latter portion of the year, typically starting around September through to October, and going through to the next months of the following year, with some of these early months seeing the highest air pollution levels (once again this is based on a large number of readings taken from many cities, as an average). Air pollution levels start to recede around March or April and can give way to the middle months of the year seeing the best (or in some cases mildly improved, still lacking perfectly clean air) readings of US AQI and PM2.5, making the beginning and end months of the year the time in which Nan is most likely to be polluted.

Which people are at higher risk from polluted exposure?

Those that are at higher risk of airborne pollutants typically have an overall poor level of health along with other comorbidities, with obesity, smoking and other detrimental habits all contributing to making an individual more at risk when it comes to pollution-related illnesses. Those with pre-existing health conditions as well as weakened immune systems (with the two often going hand in hand) are also quite at risk, along with a few other groups who will be discussed in the following question.

What health problems can arise from excessive pollution exposure in Nan?

Health issues that may arise amongst the inhabitants of Nan when they are exposed to excessively high levels of air pollution include alteration to the nervous system, particularly amongst younger children and babies, who are still undergoing their vital formative years. Many chemical pollutants and even particles have insidious effects where they can alter hormone function and have a detrimental effect on both physical and cognitive development, potentially causing babies to be born at low birth weight, with possible deformities if the mother has had excessive levels of air pollution during the pregnancy period (this is more of an extreme case example, but not one to be ruled out), as well as the infant mortality rate increasing. Other health issues, particularly amongst the elderly, but not limited to them, affect the cardiac and pulmonary systems. Increased rates of heart attacks may become more commonplace in Nan, along with arrhythmias, strokes and even premature death occurring. Other less serious issues include increased coughing, skin conditions such as acne or eczema, as well as symptoms of chronic obstructive pulmonary disease (COPD) appearing, which includes within it asthma, bronchitis and emphysema.

What are some examples of harmful chemicals and pollutants that may be found within the air in Nan?

Some more prominent pollutants that can be found in areas around Nan, as well as surrounding districts and cities, include ones that mainly emanate from combustion sources. These on their own are of an extremely large number, with open burn fires, natural disasters (such as forest fires, houses or buildings catching fire), combustion within vehicle engines as well as boilers in factories and other similar industrial sites, as was mentioned earlier in the question regarding what the main causes of polluted air in Nan are. Whilst the aforementioned open burn fires, or slash and burn farming methods as they are generally referred to, are of more significant concern in the northern regions of the country, they can still be found to a lesser degree dotted around various provinces of Thailand.

These can cause large amounts of pollutants such as volatile organic compounds (VOCs) and black carbon to be released into the atmosphere, along with the other pollutants that go into calculating the US AQI aggregate. The chemicals used to calculate this US AQI figure include nitrogen dioxide, sulfur dioxide, carbon monoxide, ozone, as well as the two main forms of particle pollution, PM2.5 and PM10. Of these two, the smaller PM2.5 is by far the more dangerous pollutant, due to its minute size of 2.5 micrometers or less in diameter allowing it to bypass the bodies defense systems and lodge deep within the tissue of the lungs (with more on this being discussed in the following health issues question). PM2.5 and some forms of PM10 can consist of materials such as water droplets and vapor, along with a variety of other liquids that can be aerosolized. Other materials include mold and fungal spores, bacteria, metals, nitrates and sulfates, along with finely ground silica dust, which can have a carcinogenic effect when inhaled. Some examples of the aforementioned VOCs include chemical compounds such as benzene, styrene, methylene chloride, toluene, xylene and formaldehyde.

Their volatile nature allows them to maintain a gaseous state at much lower temperatures, thus making them much easier to breathe, and would be encountered prevalently around inhabited areas of Nan, due to their discharge from everything from fires, cars, factories as well as even from household items. VOCs are one of the major sources of indoor air pollution and can emanate from products such as glue, paint, varnish, as well as aerosols such as deodorant, scented candles and other toiletries. These are some of the more prevalent air pollutants that may be found around Nan, with certain areas such as busy roads and intersections that see a high level of rush hour traffic having higher concentrations of pollutants such as nitrogen dioxide, ozone and black carbon. Extra care should be taken around such areas, and wearing fine particle filtering masks can aid greatly in the reduction of hazardous material inhalation.