BEIJING - Since winter, when Beijing was shrouded in smog and pollution levels went off the charts, many expatriate residents have been asking themselves one question: Should we stay or should we go?
The latter option, according to media reports and anecdotal evidence, is proving popular.
And who can blame them?
When smog hit the Chinese capital, health authorities urged children and the elderly to stay indoors, and sales of face masks and air purifiers soared.
The city's living environment is now the top challenge in retaining foreign workers, as opposed to salary or career development, said Adam Dunnett, secretary-general of the European Union Chamber of Commerce in China, citing research by the chamber.
Air quality has become a big concern, he said. "People leave for all sorts of reasons, but we inevitably hear nearly every time that one of the contributing factors is pollution."
Brenda Foster, president of the American Chamber of Commerce in Shanghai, has seen a similar trend. "Increasingly, we hear comments from members on the negative impact of air quality on their ability to attract and retain top talent."
Yet not everyone is jumping ship - some are simply adapting.
James Watson-Krips, an educational consultant from the United States working in Beijing, said he plans his daily events in accordance with the US embassy's air quality Twitter feed.
"Sometimes you give up occasions due to health concerns," he said, but he stressed he is staying put regardless. "The pollution is a fly in the ointment, but isn't bad enough to drive me out. I don't think there will be an exodus from the capital, not from my circle of friends at least."
Watson-Krips has lived in Beijing for three years and plans to remain for three more. "I came here for the city's culture, and the career opportunities are unparalleled," he said.
He is not alone.
Richard Saint Cyr, a family doctor and director of clinical marketing at United Family Hospital in Beijing, said despite the unusually serious air pollution in winter and the mounting anxiety, he intends to stay for many more years, even with his newborn son.
Air: A big concern for some in the capital
He said that since January he has noticed an increase in conversations among patients and friends about leaving China due to pollution, but he said this does not necessarily indicate a big movement of people.
Health and wellness, and a sense of happiness and fulfillment in life are much more complex than just one issue such as pollution, Saint Cyr said, adding: "I stay in Beijing because my wife and I have a very rich and rewarding cultural experience here and also our in-laws live here.
"Beijing is one of the world's most exciting places to be," he added.
People have been coming and going in Beijing for decades. Years ago, however, that probably would have meant leaving China entirely. Not now, say recruiters.
Li Li, a senior consultant at Asia-Pacific Human Resources Co in Shenzhen, Guangdong province, said more foreigners are leaving Beijing and heading to other Chinese cities.
Professionals in areas such as management, design and accounting have gone to Hong Kong, and foreign-language teachers have moved to Shenzhen and Guangzhou, she said, citing cases she has dealt with.
"The deterioration in air quality in the capital is absolutely the main reason," Li said. "Two of my foreign friends in Beijing plan to leave for their home countries due to the smog."
However, as job opportunities emerge nationwide, expats have options.
Pedro Hernandez, a Spanish computer science student at the University of Alcala in Madrid, chose a university in Shandong province for his exchange study. The 30-year-old said he plans to find a software development job in China after graduation.
Other expats are also heading south before next winter.
"In the past, Beijing would be the first or at least the second choice for foreigners who want to find a job in China," said Yang Sha, general manager at Angelina International Placement Service in Beijing, which specializes in hiring foreigners to teach languages in Chinese schools.
"Now we find Beijing is no longer appealing and foreigners prefer to work in cities in southern provinces such as Zhejiang, Fujian and Hunan," he said.
Preston Decker, 26, from the US, left Beijing for Fujian in March, citing air quality in the capital as the main reason.
"After living in Beijing for two years, it got to the point where you ask yourself if it is worth living there and damaging your health. For a person like me with no family ties, the answer is no," he said.
Decker now works as an English-language teacher in Xiamen and said he and his fiancee enjoy the fresh air and life there.
"I think it's pretty easy to scoff at the pollution when you tell yourself that you'll only be in Beijing for a short period, but once you start thinking about staying in the city for years, the weight of possible health consequences starts to add up," he said.
Oliver Twizell, a 29-year-old designer from Britain, is also considering leaving Beijing due to concerns over the air quality. "I know there are more foreigners leaving Beijing for other cities in China this summer than in previous years," he said.
Twizell said it usually takes people six months before they move elsewhere, and he thinks July could see expat relocation reach a peak.
He said a huge difference has emerged among the expat community regarding living conditions and attitude toward Beijing compared with 10 years ago, with air quality becoming the top concern.
"You see more people bringing humidifiers to work to make the office air more manageable," he said.
Twizell is considering moving to Shanghai, where he spent six years before coming to Beijing in 2012.
In January, dense smog and haze pushed the pollution index to a record high. The density of PM2.5, or particulate matter smaller than 2.5 microns, which is able to enter the lungs and blood stream, exceeded more than 900 micrograms per cubic meter in several districts of the capital, according to Beijing Municipal Environmental Monitoring Center.
According to the World Health Organisation, the safe daily level is 25 micrograms per cubic meter.
Hospitals in Beijing have reported an increase in the number of patients with respiratory problems on days when there is heavy pollution.
Improving air quality is one of the keys to retaining talented expatriates, most of whom work in high-earning professions while making a substantial contribution to the capital's development and cultural diversity.
Saint Cyr, the doctor, said daily stress and anxiety from constantly waking up to dangerously gray skies and not being able to send your children outside takes a major toll on physical health and the immune system.
"I desperately hope dramatic steps can soon be taken to improve this situation. Everyone needs hope and a silver lining," he said.