When you think of winter skies, does your mind call up images of gorgeously clear blue days and falling snow?

Thailand is hot year-round, so of course we don’t get snow.

But Northern Thailand is full of verdant mountains, so the mornings and evenings are cool during the dry season.
But the airflow is terrible—probably because of all the valleys—so it’s common for there to be fine particulate matter on foggy mornings.

What is fine particulate matter?

Fine particulate matter, also known as PM2.5, is made up of tiny air particles that float around the atmosphere.
If you breathe them in, they can get into the tiny bronchial tubes and penetrate deep into your lungs, causing bronchitis, pneumonia, asthma, or other respiratory illnesses. They’re also said to increase the risk of eye problems, neurological disorders, and other ailments.
People who suffer from allergies in particular have to be careful about PM2.5.

Agricultural burning is done during the dry season (November to February), causing people in Chiang Mai and parts of northern Thailand to experience cross-border haze pollution from neighboring countries. This, coupled with a variety of climatological, geographical, and other factors, means that the most severe air pollution all year is measured during this specific season.


When I personally traveled to the mountains of Northern Thailand to enjoy them during the relatively cool months between January and March, I found that many of the villages near the inn where I was staying still practiced traditional ways of life.
They cooked over charcoal, burned dead leaves and fields to prepare them for the next farming season, and so on. This is one problem that’s difficult to solve.

Thailand has been experiencing severe air pollution in recent years, and it’s starting to have a negative effect on the health of the population.

The problem has been particularly bad in Bangkok since 2018.
The experts say that the primary causes of atmospheric pollution are things like emissions from diesel engines, biomass incineration, and factory emissions—both within Thailand and in neighboring countries.
The problems aren’t limited to Thailand, either. Other ASEAN member states like Myanmar, Laos, and Cambodia are also dealing with them.

A news program in Thailand reported that PM2.5 values were highest in northern Thailand.
A look at the global data also shows worsening conditions in India and China, with an increasing number of people suffering from lung cancer.

There was one case of a 28-year-old physician in Chiang Mai who was diagnosed with late-stage lung cancer, even though he went to the gym every day, ate well, didn’t smoke, and got plenty of rest. He decided to look into the cause of the cancer while he was undergoing treatment.
According to a 2021 systematic review and meta-analysis by researchers, among the primary causes of lung cancer are fine particulate matter, smoking, atmospheric pollution, pesticides, and talcum powder. It’s fairly likely, then, that these have something to do with the lung cancer diagnosed in the 28-year-old doctor.

The effect of fine particulate matter on human health is an emerging problem all over the world.
Recently-developed apps allow you to check outdoor conditions in real time before you go out, and indoor air purifiers are increasingly becoming essential.
The coronavirus isn’t the only threat to our health these days. We have to wear masks and take other steps to mitigate the risk of fine particulate matter as well.