The Beijing smog feeds on itself. Whenever the city periodically disappears into a brownish-yellow haze, the traffic only gets worse. Those who are fortunate enough to own a car leave their bicycles at home, choosing air-conditioning over the unfiltered cocktail of coal smoke, particulate matter and ozone in the air.
But escaping to the relative comfort of a car's interior won't be an option for those traveling to Beijing in August 2008, when more than 10,000 athletes will compete in the Olympic Games in one of the world's dirtiest cities. China has promised what it calls "Green Games," but its pollution figures suggest the more grayish hue of smog and pollution. "The athletes could be exposed to unhealthy air pollution unless there is a substantial reduction in emissions," warns David Streets of the Argonne National Laboratory in the United States, the principal author of an article on the subject in the professional journal Atmospheric Environment.
The air is often thick with pollution in Beijing, a city of 11 million. When there is no rain or wind, ozone and fine dust accumulate, often to a rate that is two or three times the maximum levels recommended by the World Health Organization (WHO).
The fine dust stems mainly from coal power plants and factories, while vehicle exhaust gases are responsible for the ozone. The city's constant traffic jams have reduced the average speed of the cars on its streets from 45 kilometers per hour (28 miles per hour) in the past to only 12 today. Adding to the problem, more than 1,000 new cars are registered each day.
Even healthy visitors often complain of sore throats, allergic reactions and asthma. In China's 14 largest cities alone, air pollution is responsible for the deaths of 50,000 newborns each year, writes the Shanghai Star newspaper. "If you exercise," advises Ibrahim Salahat of the International Medical Center in Beijing, "you should do it inside."
Trouble for Runners, Cyclists
Children, the chronically ill, the elderly and endurance athletes like marathon runners and cyclists face the greatest risk. Endurance athletes spend hours performing at peak levels in the open air, inhaling up to 150 liters of air a minute -- more than 10 times as much as a sedentary office worker. Ozone and fine dust can cause inflammation that requires treatment with asthma and anti-inflammatory drugs. "Most symptoms subside after 24 hours," says Frank Kelly, an environmental scientist at King's College in London, "but the long-term consequential damage is still poorly researched."
"I wouldn't expect a world record in the marathon in Beijing," says Marco Cardinale, a doctor who advises the British Olympic Committee. "The issue isn't just air quality, but the combination of heat, humidity and bad air." Jacques Rogge, the president of the International Olympic Committee (IOC), does his best to downplay the problem. He argues that Beijing isn't the first Olympic host city with environmental problems. Athens (2004), Los Angeles (1984) and Mexico City (1968) aren't exactly known for their pristine air.
But information about which athletes will end up gasping for air at which pollution levels seems to be a carefully guarded secret. Neither trainers nor officials are especially interested in divulging the details, and much of the available information is anecdotal.
For example, says Randy Wilber, a manager of the US Olympic team, more than 20 percent of US athletes reacted to the smog in Athens with breathing difficulties. In Los Angeles, British runner Steve Ovett collapsed with respiratory problems after the 800-meter race. Ovett is convinced that pollution was the culprit. "Many suffered from the bad air, but hardly anyone said anything," Ovett complained in an article in the scientific journal Nature.
The notion that bad air is harmful to athletes' lungs was demonstrated as far back as 1904 during the Olympic marathon in St. Louis. Only 14 of 32 competitors were able to complete the course through the city's dusty streets, running between cars and horse-drawn carriages. Thirteen kilometers (eight miles) shy of the finish line, American runner William Garcia collapsed and almost died of a gastric hemorrhage -- he had swallowed too much road dust.
The 'Green Games'
Nevertheless, Beijing's city government steadfastly believes in its "Green Games." It plans to invest €2.5 billion ($3.36 billion) in improving the city's air by the time the Olympic games begin. Heating in many households has already been converted from coal to natural gas, and a Beijing steel mill is currently being relocated to an outlying area.
Still, experts remain skeptical. They believe that even if Beijing were able to take all cars off the road and shut down its factories and air-conditioners for the duration of the Olympics, it wouldn't be enough. Depending on the wind direction, between 50 and 70 percent of the city's dangerous fine dust isn't generated in Beijing itself but in neighboring provinces, especially Hebei. When it comes to ozone levels, outside areas are responsible for 30 percent of the pollution in the Chinese capital. These are the numbers Argonne scientist Streets has come up with in a simulation. He sees an "urgent need" for new strategies to control emissions.
And yet the city government remains confident, even issuing periodic progress reports on its supposed successes. For example, Beijing's government claims, it has managed to increase the number of "blue sky days" -- when smog levels are lower than normal -- to about 240 a year.
Of course, many Beijing residents can only chuckle asthmatically when confronted with such figures.