Lingering smog appears to be taking another toll on China by driving the affluent and bright overseas, a signal of public discontent over perceived failures to address pollution concerns.
Analysts predict the trend of "smog emigration" is expected to continue, as improvements to air pollution through economic restructuring will not take effect in the short term.
Smog blanketed much of northern and eastern China for almost a week until rain and wind began to disperse the pollution late Wednesday.
Data from Beijing's environmental monitoring center showed the average levels of PM2.5 was 450 in the downtown Wednesday, nearly 18 times World Health Organization (WHO) guidelines.
While sales of masks and air filters have soared, many have taken to social media to declare their hopes of emigrating, as they see no immediate end to the pollution.
Several emigration agencies used the opportunity to promote their business.
An advert on the website of Kino International, a Beijing-based emigration consultancy, showed photos of clear skies overseas contrasted with almost invisible skylines in Beijing.
The advert reads that China has seen "three waves of emigration," referring to laborers, technicians and investment émigrés, and the smog is the driver for a fourth wave.
Chen Zhiyu, a partner at Beyour.API, a consultancy for emigration and property purchase in Australia, said Wednesday that the past week has seen a 300 percent increase in clients seeking emigration advice.
"Concern over environmental pollution is the primary motivation for emigration, with better education and legal systems remaining deep-rooted causes for their decision," Chen said, adding that more than 80 percent who want to move cite pollution as a major concern.
An annual report on Chinese international migration, released last month by the Center for China and Globalization (CCG), found that nearly 70 percent of respondents said pollution was a main reason for leaving.
Wang Huiyao, director general of the CCG, said Wednesday that the smog has not only prompted the Chinese elite to leave the country, but it is deterring foreigners from seeking opportunities in the fast growing economy.
Like the emergence of climate emigration as a result of global warming, there is definitely a phenomenon of emigration driven by pollution, Wang said, noting it will last for five to 10 years. An increase in Chinese people vacationing abroad has also raised their expectations of a livable environment.
The profile of those choosing to leave has also changed, said Chen. The majority of their clients are now younger, often couples in their 30s with young children, who are not so wealthy. "They want to provide their offspring a better environment by moving," he noted.
Yang Fuqiang, a senior advisor on climate and energy at the Natural Resources Defense Council, said that Beijing's situation is similar to that in Los Angeles in the 1950s and 1960s.
It took Los Angeles some three decades to curb the pollution, and average PM2.5 levels in the city are now between 15 and 20.
"If Beijing follows through on its current pollution-curbing measures, average PM2.5 levels will fall under the WHO guidelines of 25 micrograms per cubic meter between 2025 and 2030," Yang said, noting it will take another decade for Beijing to see similar PM2.5 readings as that of Los Angeles today.
The severe smog has prompted China's top leadership to step in.
During a visit to a historic Beijing neighborhood Tuesday, President Xi Jinping called for strengthened efforts to curb air pollution by treating "both symptoms and root causes."
Earlier this month, while chairing a cabinet meeting, Premier Li Keqiang said smog is the most mentioned word on the Internet, and the government cannot evade this problem.
According to studies, the smog can drive down China's GDP growth.
A recent report from China Agriculture University said it could adversely affect crop growth as pollution blocks sunlight. If the smog continues worsening, China's food supply will see a threat similar to a "nuclear winter," the report warned.