As Beijing air pollution worsens, some American expats clear out BEIJING - After nearly two decades in Beijing, David Wolf knew it was time for a change when his 11-year-old son, Aaron, somberly asked him, "Dad, when you were growing up, did you ever have PE outdoors?" Wolf had grown up in smog-choked Los Angeles in the 1970s, but even that wasn't nearly as bad as Beijing today. His son, like many young students in the city, has been kept inside for months, with the luckier children getting the chance to exercise under huge air-filtered domes that their international schools have built. Later this month, when school lets out, Aaron and his mother will move to Southern California for good, and Wolf begins a new way of doing his consulting work, splitting his time between Beijing and their new home at Channel Islands Harbor. "I want them to leave before they hate this place," Wolf, 49, said on a recent morning as he checked Beijing's air quality on a smartphone app, something that many people here, expats and locals alike, routinely do several times a day. After a brutal winter, when Beijing and some other cities in northern China logged their worst air pollution readings on record, and a somewhat better but still unacceptably unhealthful spring, some people are starting to escape from Beijing. Although Beijing officials have said sulfur dioxide counts have dropped in recent years, other major air quality measures and the soupy haze that often blankets the city tell a different story. China's rapid economic growth and urbanization have brought many more pollution-spewing vehicles to the city, and Beijing also has the misfortune of being surrounded by mountains that trap the soot-filled air from neighboring provinces that churn out huge amounts of steel, cement and other products for the domestic market. No one knows how many have fled or made concrete plans to leave, but expats who have been in China's capital a while seem to know at least a person or two who are getting out, and many more who are talking about it. So far it has been a trickle rather than an exodus. With China's economy still growing much faster than other major economies - and Beijing in many ways at the center of it all - it isn't easy for people, especially executives, to walk away from the opportunities here. Residents of China "know there are issues of food quality, air quality, even water and rice quality. This is a given," said Simon Wan, the global head of Cornerstone International Group, a major executive search firm based in Shanghai. "They are taking all kinds of protection," such as wearing surgical masks and buying air filtration equipment. As for potential new arrivals to China, Wan said, "this is not a deal breaker.... The reality is that in the U.S. and Europe, the job scope and size are not as interesting. Still, China's poor air is becoming an increasing economic concern, with sickness and stay-indoors alerts cutting into productivity and profits. Given a choice, senior managers are asking to work in Shanghai rather than Beijing, in part because of the difference in air quality. The American Chamber of Commerce's membership keeps growing in Shanghai while flat-lining in Beijing. Hardship pay for being based in China, a thing of the past, is starting to come back, says Christian Murck, the chamber's president in Beijing. Groups like the American and European chambers here have raised public concerns, and with many Chinese citizens increasingly vocal about pollution and health worries, China's political leaders have pledged to take tougher action. Saying that the country will not sacrifice the environment for short-term economic gains, President Xi Jinping has vowed to punish officials who approve projects that cause serious pollution. Last week, the State Council, China's equivalent of a Cabinet, adopted a set of measures to reduce air pollution, including an order that heavy-polluting industries such as steel and petrochemicals release environmental data to the public and gradually comply with international emission limits. In the run-up to the 2008 Olympics in Beijing, factories around the city were ordered to curtail production, and use of cars, which have been multiplying, was restricted as well. But policies that would make more-lasting reductions in emissions of burning coal and fuel, through new technologies and standards, have been blocked by China's petrochemical, steel and other heavy industry groups. "We are not talking about companies that can be easily pushed around," said Murck, referring to giant state-owned enterprises that dominate the economy and are politically well connected. Murck, 70, himself is leaving Beijing this summer, returning to New York after 17 years in mainland China. He says it wasn't because of the pollution, although he recalled one winter day when the fine particulate matter in the air in central Beijing - the so-called PM 2.5 measure - surpassed 700 micrograms per cubic meter, far into the hazardous zone. That same day, he said, the PM 2.5 reading was 19 in New York City. "I thought to myself, 'Well, one more reason to go to New York,'" he said. As recently as late May, Beijing's air quality measure almost reached 300, according to the American Embassy in Beijing. A reading above 300 is considered hazardous, although the U.S. Centers for Disease Control and Prevention said last year that the average fine particle pollution count at 16 airport smokers' lounges was 166.6. The U.S. Environmental Protection Agency in December set a new national standard for PM 2.5 at 12, down from 15, established in 1997. Calvin Tchiang of the Bay Area and his wife, Melody, who was raised in Taiwan and Los Angeles, moved to Beijing several years ago. Fluent in Chinese, the couple seemed to have everything going for their budding careers. Calvin worked for an investment company developing Chinese partners interested in biotech; Melody had a job as a translator. But life in Beijing began to change about a year ago when they had a baby, Xavier, and the pollution became intolerable. The Tchiangs put three air purifiers in their apartment, one for each room. The machines whirred 24 hours a day. When the PM 2.5 dropped under triple digits, which was rare, they opened the windows and took their baby outside. When they went out, though, the couple wore similar Darth Vader-like respirators, Calvin in black and Melody in red. Melody found herself checking the PM 2.5 reading several times a day. Whenever it hit 300, she would not go out at all. "There were instances when I became a recluse," Melody said. The Tchiangs returned to the U.S. in April, settling near Cincinnati. Calvin is still with the same firm but doing more investment work that can be undertaken from the U.S. Melody is content for now to be a stay-at-home mom. They say it hasn't been easy readjusting culturally. But one thing they don't worry about is taking their 11-month-old outside. "I was just out today walking in the park with a few moms," Melody said on a recent evening. Calvin added, "We appreciate just walking to the local supermarket."