On a Sunday, when Hanoi's air quality index (AQI) fell to 43, Claire Holmes, 28, an English teacher, was excited because she could finally go out and get some fresh air after spending days indoors either at home or work as she sought refuge from the pollution.

"I was coughing and had chest pain sometimes, my throat felt scratchy, and the doctor said these were all because of the particles in the air," she says.

These symptoms directly affected her job since she had to speak loudly while teaching. Sometimes, her hoarseness prevented her from going to work, which stressed her out.

She thought about leaving Vietnam several times to escape the dirty air, but quickly abandoned the idea each time. There are not a lot of other places, not even her native U.S, where Claire can get such a well-paid job.

With a monthly income of $2,500, she has a good life in Hanoi because "everything in Vietnam is inexpensive."

"My background is psychology, and I could not find a job in my country. But here, things are easier."

Yet living with the lethal air and checking the AQI daily did not make much sense either. On September 26 Hanoi's AQI was 204, making it the most polluted city in the world. She found a neat solution: escaping to the central city of Da Nang, where she can continue her teaching job but avoid the capital’s pollution.

Claire is not the only foreigner for whom economics has trumped the environment in Vietnam.

With the cost of living for foreigners ranging from $700 to $1,400 per month, the country is among the most affordable places for them to settle down, according to a report by global cost of living database compiler Numbeo. The number of foreigners living in the country rose from a mere 12,600 in 2004 to 83,500 in 2015.

Steward Fraser, a recruitment expert in Ho Chi Minh City, says the pollution is harmful, but being jobless is the worst. Finding a way to live with the dirty air, such as using air purifiers and masks, is what he has been doing.

In his apartment in Thao Dien, a place favored by foreigners, he always turns on the air purifier and never opens the windows.

A foreigner wears a mask as she walks her dog along the West Lake in Tay Ho District,
Hanoi, in the morning of September 30, 2019. Photo by VnExpress/Ngoc Thanh.

Most of his foreign neighbors are doing the same thing, he says. Some families even have two or three of them and keep indoors to reduce the exposure to the polluted air.

Many of them also cannot imagine moving out of Vietnam because they have been living in the country for a long time and put down roots.

Luke Evan, a British businessman in Hanoi, has been living in Vietnam for more than a decade, and relocating has never crossed his mind since most of his connections and friends are here.

He says he was a "pollution innocent" when he moved to the country from the U.K., and started to obsessively check the AQI daily and wear a mask when he went out.

"Vietnam is my home now. If I leave my home, where can I go? Once you live with the dirty air, you have to learn to deal with it.

"We decided to go to the gym instead of going out to run. I hate the fact that I have to check the AQI whenever I want to go out, but I have no choice. Sometimes I miss running outside, so I opted for a mask.

"Huong, my wife, is keen on the idea of living in Vietnam because her family is here; life is good here for us, except the air; we can deal with it. We are not ready to abandon everything we have in Hanoi."

Nostalgia for clean air

On Tuesday the Vietnam Environment Administration said the air quality in the capital has been worsening since the beginning of this month. 

On several mornings the AQI, which measures air quality, exceeded 200, which is unhealthy for all. The agency does not expect the air quality to improve in the next few days. 

In HCMC, the AQI has fluctuated between 54 and 133 in the last few days. On Friday morning it was 123, or unhealthy for sensitive groups.

Earlier last month several diplomatic missions in Vietnam warned their citizens about severe air pollution in Hanoi and HCMC, advising them to check the AQI and protect themselves when traveling to the two cities. 

"High levels of air pollution, up to and including hazardous levels, occur in Vietnam, particularly in the biggest cities, and may aggravate heart, lung or respiratory conditions," the British embassy in Hanoi cautioned. It also advised citizens to check the AQI on the Internet. 

The air quality monitor at the German embassy also indicated that the air quality was in the "unhealthy" category on many days last month. The mission warned that long-term exposure to air pollution mainly affects the respiratory and inflammatory systems but could lead to more serious problems such as heart disease and cancer.

An air pollution monitor near the West Lake in Hanoi.
Photo by Reuters/James Pearson

WHO said more than 60,000 deaths in Vietnam in 2016 due to heart disease, stroke, lung cancer, chronic obstructive pulmonary disease, and pneumonia were linked to air pollution. 

According to the Ministry of Natural Resources and Environment, the problem persists due to millions of personal vehicles on streets across the country, construction and heavy industry like steel works, cement factories and coal-fired plants.

Hanoi has more than five million motorbikes and the number of private vehicles is increasing at the rate of 4.6 percent a year. HCMC has 8.5 million motorbikes.

The government also launched an action plan to control the air quality, involving numerous agencies and a host of solutions to tackle air pollution, such as green production and investment in new technologies.

But for the moment, for both locals and foreigners in Hanoi and HCMC, staying inside, sometimes with expensive air purifiers, is a better option.

Evan says: "We can’t use masks or purifiers for the rest of our lives. I hope the problem will be solved soon."