How Hanoi can deal with its fine dust crisis

For those afflicted, the refrain is almost always the same: "The air is toxic."

On the surface, the weather does not seem to be the issue. It is not too cold, nor is it scorching hot. In fact, the autumn air can be quite pleasant, and photographers are capturing the serene beauty of sunlight filtering through the trees. Yet, beneath the surface, the true culprit of this rising health crisis is the invisible enemy that lingers in the air: fine dust.

When the air is laden with these tiny particles, sunlight can only be seen as sharp beams, what photographers call "rays". But for ordinary people, these particles, small enough to escape detection, are the root cause of respiratory and cardiovascular problems that have worsened during the fall months in northern Vietnam.

Dust pollution is not a new issue. It has always been there, occasionally flaring up and causing public concern, only to fade from memory. Instead of addressing it through research and effective policy, the issue is allowed to linger year after year, floating in the air and making people sick.

When I was in school, public health lessons focused on waste, sanitation, and the "three pests": flies, mosquitoes and rats. Dust was only mentioned in the context of factory workers inhaling harmful quantities of dust and developing pneumoconiosis. In later years, environmental health expanded to include new pollutants: chemicals, pesticides, water contamination, even noise pollution. But fine dust remained largely neglected.

It was not until the 2010s that some researchers started to look at dust pollution more seriously. But even as this issue became more apparent, the public still largely ignored it, until 2019. That year, IQAir, an air quality monitoring organization, released a report ranking Hanoi as having the second-highest level of fine dust pollution in Southeast Asia, behind Jakarta. The report sparked outrage, with many dismissing the findings as biased or localized.

But this report, however contentious, shed light on a long-overlooked issue: fine dust. Many people were hearing the term "PM2.5" for the first time. Suddenly, the idea of air quality was no longer an abstract concept; it became something personal, something people could track. Apps like IQAir's air quality monitor became widely downloaded, and more people began wearing N95 masks in a bid to protect themselves.

In response, the government proposed a range of solutions: relocating polluting industries out of the city center, enforcing stricter emissions standards for vehicles, and requiring construction sites to take measures to reduce dust. Yet, these solutions remain largely theoretical. After all, the world was soon swept up in the Covid-19 pandemic, which diverted attention away from air quality, and the policies proposed to combat pollution were left gathering dust.

To understand just how dangerous fine dust is, it is important to grasp its size and impact. Fine dust particles are minuscule, so small that they bypass the body's natural defenses, penetrating deep into the lungs and even entering the bloodstream. These particles are linked to a host of diseases, from respiratory issues like bronchitis and asthma, to cardiovascular problems like heart attacks and strokes. In fact, a 2017 study by Aaron Cohen and colleagues on the Global Burden of Disease showed that deaths from exposure to PM2.5 in Vietnam increased from 26,000 people per year in 1990 to more than 42,000 per year by 2015.

The air quality index (AQI), which many countries use to assess air pollution, is another way to understand the severity of the problem. Using an international standard created by the U.S. Environmental Protection Agency (EPA), the AQI measures five key pollutants, including fine dust. An AQI of 0-50 is considered good; 51-100 is acceptable; 101-150 is not good for sensitive groups; 151-200 is unhealthy, and people are advised to stay indoors; anything above 200 is hazardous, often marked with a purple color.

Smog covers an area over the Red River in Hanoi in December 2023. Photo by VnExpress/Ngoc Thanh

In 2019, Hanoi's fine dust levels were among the highest in Southeast Asia. Five years later, by September and October 2024, the situation had worsened. The city's AQI has frequently been in the red, with some days even reaching purple: levels that indicate severe health risks.

To fight back, authorities recommend staying indoors, keeping windows closed, using air purifiers and wearing masks. But these recommendations remain abstract solutions to a very real problem. In reality, millions of Hanoi's residents still have to go out every day, working in the very air that's making them sick, contributing further to the pollution in the process.

While these solutions are sound in theory, their implementation is painfully slow. The truth is, Hanoi needs more than just good intentions. To truly tackle the problem of dust pollution, we need bold, decisive action.

The most important step is to reduce population density in the city center. Fewer people means fewer cars on the road and more room for green spaces. Green spaces, in turn, can help absorb toxic pollutants and capture dust. The average green space per person in Hanoi's central districts is dismally low: under two square meters per person, well below both the Vietnamese standard of 6-7 square meters and the international standard of 15-20 square meters.

This is no coincidence. Hanoi's historical center lacks space for schools and parks, and many of the proposed solutions, such as relocating industries to the outskirts, have been slow to materialize. Meanwhile, the rapid urbanization of Hanoi, with new high-rise buildings added year after year, has only exacerbated the problem, creating more traffic, more pollution and more crowding.

The government has outlined plans to develop more parks, increase green spaces and limit the number of vehicles in the city center, but these measures are still far from being realized. The pace of implementation simply has not kept up with the city's growth.

So, what can be done now? There are practical steps that every citizen can take. For example, all vehicles should be cleaned regularly to prevent dirt from being kicked up into the air. We could set up automatic car-washing stations on the outskirts of the city to wash vehicles before they enter the more polluted urban core. Roads should also be washed daily to reduce dust.

We should also begin phasing out gasoline-powered vehicles, particularly motorcycles, from the city center. This has been discussed in policy circles, but it requires a shift in how we think about mobility, especially given how many people still depend on motorbikes for their livelihoods. This means the government will need to develop social welfare programs to support those affected.

Finally, we can expand the city's green spaces by utilizing rooftops. With little room left for parks, Hanoi's rooftops are a largely untapped resource. Encouraging residents to plant small trees or vines on their rooftops could help combat both pollution and the heat, while increasing the city's overall green space.

Cities like Beijing, once infamous for their pollution, have successfully reduced their air pollution levels in recent years. If they can do it, Hanoi can too. But it will take more than just talking about the problem. It will take action, from both the government and its citizens.

If we all do our part, maybe one day, Hanoi can breathe again.

*Doctor Quan The Dan is deputy director of Tri Duc Thanh General Hospital in Thanh Hoa Province.