

By Nguyen Dang Anh Thi   January 21, 2021 | 07:00 am GMT+7
Nguyen Dang Anh Thi

Nguyen Dang Anh Thi

So when we talk about fine dust, let us not forget that coal-fired power plants are a major producer of this killer.

On learning that China had spent $17.3 billion to clear the air in its capital Beijing for the 2008 Summer Olympics, I decided to visit the city two years later.

Beijing, where the Great Wall of China stands, had been on my go-to list for years. But I kept putting it off because The Lancet, a peer-reviewed general medical journal that's among the world's oldest and best-known publications, once called the city "the air pollution capital of the world" with 400,000 deaths a year from dirty air.

Then I saw pictures of the Olympics with clear blue skies in Beijing. That sky was my green light.

That sky, the day I arrived, had a pale, blue-grey color, though it was sunny at around noon.

"But it is more beautiful than other days," said my Chinese tour guide.

For the Games, China had ordered businesses to temporarily shut down more than 50 coal-fired power plants and 300 factories, apart from limiting the number of vehicles on the streets in its bed to minimize air pollution.

Two years after the event, the haze and fog in the air of Beijing caused breathing difficulties and a tightness of the chest for me and others in my group.

Not long before my trip, a friend who had also traveled from Hanoi to Beijing had to cut the journey short after not being able to breathe normally and suffering a nosebleed.

"After the temporary Olympic beauty, everyone had to go back to the old pig trough," the tour guide said in a feeble attempt at humor.

"If only Beijing could have the fresh air of Hanoi," he told me after seeing a snapshot I took of the sky when I was riding the escalator at Noi Bai International Airport to get ready for the flight to Beijing. That day, the autumn skies of Hanoi were clear and blue.

The tour guide continued the conversation, saying a blue sky was a rarity in Beijing. This cloudy, grey shade was their constant companion. The clouds were dust clouds, not the one that is naturally formed by water vapors.

The dust, "fine dust" or "fine particle," is a term describing airborne particles that have a diameter less than human hair (around 2.5 micrometers - µm). Because of its microscopic size, the PM2.5, or fine inhalable particles with diameters that are generally 2.5 micrometers and smaller, cannot be seen with the naked eye.

Those particles could stay in the air from a few hours to a few dozen days. Then thanks to the wind, fine dust can travel hundreds to thousands of kilometers away from their emission source. When this accumulates in high concentrations, it causes diffused light and makes the sky pale and even opaque.

And because it is so small, find dust cannot be prevented by masks or any conventional measure.

Yet, despite its size, fine dust is in fact an invisible, silent killer – an assassin.

Deadly impacts

Via the respiratory tract, fine dust easily penetrates deep into the lungs, travels along blood vessels to all the "caves and alleys" in our bodies, even the brain and the fetus.

In the long run, it can cause heart attacks, strokes, cancers and memory losses, not to mention regular symptoms like cough, tightness of chest, shortness of breath, and chronic diseases of the respiratory system as well as the eyes. The elderly and children, people with cardiovascular and respiratory diseases are especially vulnerable to this "assassin."

So what are the sources of fine dust? Here’s a selection: the burning of fossil fuels like coal, gasoline, oil, firewood, straw and waste, forest fires, volcanoes and sand storms.

And what does this mean for us?

It means that Hanoi, the capital of Vietnam, no longer has the clear, blue sky I saw the day I left for Beijing. Air pollution has become a serious health hazard and an increase in fine dust is responsible.

Air pollution as seen from a high-rise building in Thanh Xuan District, Hanoi, December 8, 2020. Photo by VnExpress/Ba Do

Smog smothers streets with high-rise buildings in Thanh Xuan District, Hanoi, December 8, 2020. Photo by VnExpress/Ba Do.

In the first days of 2021, Hanoi has made headlines repeatedly for the air pollution that is visible to the naked eye.

IQAir, a Swiss air quality technology and monitoring company, said Hanoi's AQI climbed to an "unhealthy level" of 185 on January 6, making it the fifth most polluted city in the world.

The city's level of PM2.5 was 121.3 micrograms per cubic meter (μg/m3) of air that day.

Released in March last year, the 2019 World Air Quality Report by IQAir said that for the first time, Hanoi had surpassed China’s Beijing, the world’s most suffocating capital just a few years ago, to become the world’s seventh most polluted capital city.

Hanoi’s worsening air quality saw its average PM2.5 level in 2019 rise to 46.9 micrograms per cubic meter of air from 40.8 in 2018.

Also in 2019, Vietnam ranked 15th in the list of 98 countries and territories with the worst air quality in the world and second in Southeast Asia behind Indonesia with an average annual PM2.5 concentration of 34.1 µg per cubic meter.

That figure was 1.4 times higher than the permitted level in Vietnam and 3.4 times higher than the recommended level by the World Health Organization.

In fact, Hanoi, Ho Chi Minh City, Hue and Da Nang, all had PM2.5 levels higher than the levels regulated by both Vietnam and the WHO.

Vietnamese lungs do not have any outstanding capacities compared to their brethren elsewhere, but they have been forced to suffer much more than they should.

The Ministry of Natural Resources and Environment and local authorities have been calling for residents to limit construction work, traffic, the burning of straw (in the fields) and the use of honeycomb charcoal.

Elephant in the room

I have nothing against this, but such moves will never address the problem fully.

The reason is simple. They ignore the elephant in the room: coal-fired power plants, a major source.

Construction dust, traffic emissions, straw and honeycomb coal burning are all sources of relatively low levels of emissions of fine dust, but because they are all easily seen by the public eye, they are easily blamed.

Studies around the world have proven that only about 11 percent of construction dust is fine dust, while a majority of that type of dust are particles larger than 10 µm, and therefore is pulled by gravity to the ground. It cannot spread to great distance.

The amount of gasoline consumed by 3.5 million cars and 50 million motorbikes in Vietnam is less than half of the amount of charcoal burned each year; and the ash content in coal is several thousand times higher than in gasoline. The scale of burning straw in the field or or honeycomb coal is not almost insignificant compared to the burning of fossil fuels.

Therefore, despite their contribution to fine dust pollution in Hanoi or HCMC, the above sources are not the biggest culprits.

According to the International Energy Agency, coal-fired projects are the leading polluter in Vietnam, followed by factories, construction and transportation.

In 2019, Vietnam consumed more than 84 million tons of charcoal, 3.4 times higher than 10 years earlier. Thermal power plants used up 64 percent of this quantity, while all other sectors, including industrial production, consumed the rest.


Despite its emission treatment system, the most modern coal-fired power plant in Vietnam, which has a capacity of 600 MW, still emits nearly 15 tons of matter creating fine dust every day. So plants using more outdated technology would emit even more of this toxic substance into the air. In all, the country currently has more than 21,000 MW of coal-fired thermal power capacity in operation.

It is also worth noting that 90 percent of the national coal-fired thermal power capacity comes from plants that are operating in a diameter of 200 km (124 miles) around Hanoi and 250 km around HCMC.

Hanoi and HCMC are surrounded respectively by 24 and 11 coal-fired plants.

In a joint study published in ScienceDirect, a website which provides access to a large bibliographic database of scientific and medical publications of the Dutch publisher Elsevier, scientists from the Chinese Academy of Sciences and Peking University said that in adverse weather conditions, coal-fired power plants cause severe dust pollution (40 µg per cubic meter) that can reach as far as 250 km.

While it is easy to find and read thousands of studies to see the connection between air pollution, fine dust and thermal power plants by researchers from many different countries in international journals, isn’t it surprising that such studies are very rare, if not nonexistent in Vietnam?

Spending money on monitoring stations will only help Vietnam achieve the goal of confirming the level of air pollution and giving out warnings, but will never address the core problem.

The government should use its funds wisely, to fund studies that identify major sources of fine dust emissions so that suitable solutions can be devised.

The first step is to locate the source of pollution and the next step is to seriously investigate and find the right solution based on scientific evidence.

It is already very late, but the golden rule in medicine still applies – correct diagnosis has to precede correct treatment.

We have to do the same thing with eliminating fine dust – or we’ll bite the dust in sickening ways.


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