China's unsolved riddle is how to reconcile fast economic growth with environmental protection. But Beijing's Olympic deadline means the city needs an immediate answer. EVERY day, monitoring stations across Beijing measure air pollution to determine if the skies above the Chinese capital can officially be designated blue. It is not an act of whimsy: with Beijing preparing to play host to the 2008 Olympic Games, the official Blue Sky ratings are the city's own measuring stick for how well it is cleaning up its polluted air. December 27 did not bring good news. The grey, acrid skies rated an eye-reddening 421 on a scale with 500 as the worst. The next day it was 500. Both days far exceeded pollution levels deemed safe by the World Health Organisation (WHO). In Beijing, officials warned residents to stay indoors until December 29, but the residents are accustomed to breathing foul air. One man flew a kite in Tiananmen Square. For Beijing officials, December 27 was especially depressing because the city was hoping to celebrate an environmental victory. In recent years, Beijing has steadily increased its Blue Sky days. The city needed one more, defined as scoring below 101, to reach its goal of 245 Blue Sky days this year. (It finally did so on December 30.) These improving ratings are how Beijing hopes to reassure the world that Olympic athletes will not be gasping for breath next August. "We're definitely hoping for the best," said Jon Kolb, a member of the Canadian Olympic Committee, "but preparing for the worst." For the world's Olympians, Beijing's air is a performance issue. The concern is that respiratory problems could impede athletic performance and prevent records from being broken. For the city's estimated 12 million residents, pollution is an inescapable health and quality-of-life issue. Scepticism about the validity of the Blue Sky ratings is common. Moreover, the concern is whether the city can clean itself up long after the Games are over. Beijing has long ranked as one of the world's most polluted cities. To win the Games, Beijing promised a "Green Olympics" and undertook environmental initiatives now considered models for the rest of the country. But greening Beijing has not meant slowing it down. Officials have also encouraged an astonishing urbanisation boom that has made environmental gains seem modest, if not illusory. Beijing is like an athlete trying to get into shape by walking on a treadmill yet eating double cheese burgers at the same time. Polluting factories have been moved or closed. But auto emissions are rising as the city adds up to 1,200 new cars and trucks every day. Dirty, coal-burning furnaces have been replaced, lowering the city's sulphur dioxide emissions. But fine-particle pollution has been exacerbated by a staggering citywide construction binge that shows no signs of letting up. China's unsolved riddle is how to reconcile fast economic growth with environmental protection. But Beijing's Olympic deadline means the city needs an immediate answer. The Communist Party envisions the Games as a public relations showcase and is leaving no detail untended. Scientists are cross-breeding chrysanthemums to ensure that flowers bloom in August. Now Beijing is also going to try to manipulate air quality. For months, scientists have treated the city like a laboratory, testing wind patterns and atmospheric structure, while pinpointing local and regional pollution sources. Olympics contingency plans have been approved for Beijing and surrounding provinces. Details have not been made public, but officials have discussed shutting down factories and restricting traffic during the Games. "We are determined to ensure that the air conditions meet the necessary standards in August 2008," Liu Qi, president of the Beijing Organising Committee for the Games, told the International Olympic Committee's (IOC) executive board in December. Beijing officials say the Olympics will have a lasting and positive environmental legacy on the city. Officials of the IOC acknowledge that air quality remains a problem but they say the air would be far worse without the improvements made for the Games. "The general trend is improvement," said Simon Balderstone, an environmental adviser for the IOC. But pollution is expected to remain a major, long-term challenge as Beijing's population may eventually exceed 20 million. Scientists also say the city will never be able to clean itself up if surrounding industrial provinces are not cleaned up, too. Blue skies, in other words, will remain a challenge. Beijing's environmental programme, which began in 1997, has become the centerpiece of the city's Olympic environmental commitments. Today, urban sewage treatment has doubled since 2001. Use of natural gas has jumped 38-fold as city officials have converted thousands of dirty, coal-fired furnaces and boilers. Factories have been shut down or relocated to the suburbs. Millions of trees have been planted. "For many years, the city had few environmental rules," said Balder-stone, the IOC environmental adviser, who regularly consults with Beijing officials. "It's like they are playing catchup on a lot of these measures." URBAN BOOM But Beijing's Olympic bid also intensified a stunning urban boom. Since 2000, Beijing's gross domestic product has jumped 144 per cent, according to Olympic officials. New office buildings and apartment towers seem to rise every week. More than 158 million square metres of new construction has been started since 2002, most of it unrelated to the Olympics. "I think there will be another 20 to 30 years of urbanisation," said Wu Weijia, a professor at Tsinghua University's Institute of Urban Studies. "The scale of construction in Beijing will not slow down after the Olympics." Meanwhile, an explosion of car ownership has wrought gridlocked traffic and a halo of auto fumes. Beijing now has more than three million vehicles and is adding more than 400,000 new cars and trucks each year. Beijing's problems are compounded because its public transportation system was ignored for years. Now, the city is expanding subway lines and finishing a rail line from the airport to downtown, but car ownership is expected to keep rising. Kolb, the Canadian Olympic official, spent much of August in Beijing trying to discern the question hanging over the city as the Games approach: Has air quality actually improved? An environmental physiologist, Kolb visited several stadiums, and sneaked into a few others, to measure pollution with a small monitoring device. On August 5, his measurement of fine particles pollution, or PM10, reached 200, roughly four times above the level deemed safe by the WHO. "We're worried," Kolb said. Of Beijing's air pollution, he added: "There's no doubt about it. It's off the charts." A decade ago, Beijing introduced the Blue Sky programme to measure sulphur dioxide, nitrogen dioxide and PM 10. Under the system, monitors take regular readings of each pollutant and then calculate a 24-hour average for each. The daily Blue Sky rating is determined by whichever pollutant has the highest 24-hour average. In 1998, Beijing recorded only 100 Blue Sky days. Each ensuing year, the city has improved the number. Cleaner coal has helped reduce sulphur dioxide by 25 per cent since 2001. Nitrogen dioxide is also down. But Beijing's biggest problem is PM 10 and other particulates, which are attributed to construction, industry and cars. Kolb said Olympic athletes were worried about ozone, which can inflame the respiratory tract and make it more difficult to breathe. But Beijing's monitoring system does not measure ozone, nor does it measure the finer particulates known as PM 2.5. Studies are on to assess the health impact of pollution in Beijing. A 2003 study warned that air pollution could be a major contributor to premature deaths related to chronic pulmonary disease, especially in the winter. Another study showed that visits to hospital emergency rooms rose on days with higher pollution levels. Hu Fei, Director of the Institute of Atmosphere Physics in Beijing, said any concern was misplaced. "Don't worry about the Olympics," Hu said, expressing confidence that contingency plans would produce clean air for the Games. "We need to be concerned about the long term." Hu said finding a long-term fix is difficult because of Beijing's geography. With mountains on three sides, Beijing depends on strong winds to disperse pollution. Yet winds also draw pollution into the city. The study in atmospheric environment estimated that as much as 60 per cent of the ozone detected at the National Stadium could be traced to outside provinces. "Beijing is a pollution source itself, and it is surrounded by other pollution sources," Hu said. "When you have wind, it brings in pollution from other sources. When you don't have wind, the local pollution cannot disperse." Xu Jianping, 55, a business consultant, does not need to be told that Beijing is overrun with cars and construction. He is an avid in-line skater who enjoyed skating to work until pollution left him spitting out black phlegm. He went online and ordered a gas mask. "But I don't want to wear it," said Xu, fearing his mask would be misinterpreted as a protest against the Olympics. "It would hurt China's image." So until the Games are over, Xu is taking the bus to the office. He plans to vacation outside the city during the Games. Then, when life in Beijing returns to normal, he plans to resume skating to work - with his mask, if necessary. ?