A thick soup of eye-stinging smog hangs over Beijing's Olympic Stadium, without any blue sky in sight.
With six months to go before the Olympic Games, Beijing's air pollution on most days is off the charts, and in August, high humidity only exacerbates the problem.
China's growing passion for cars, and its citywide construction boom, are largely to blame. There are 1,000 new vehicles in the capital every day.
Today, Chinese media reported that Beijing will close more than 150 gas stations and oil depots, by the end of May, to decrease air pollution.
In three months, the city also plans to shut down city construction sites. According to the official Web site of the Olympic Games, Zhou Shengxian, head of the State Environmental Protection Administration, said the government will close several "coal-fired power plants, as well as steel mills and cement plants, to cut emissions of the acid rain-causing pollutant."
Olympic bronze medal-winning marathoner Deena Kastor worries she will be forced to gulp down huge quantities of polluted air, should she make this year's U.S. marathon team.
"It's going to be very taxing in the endurance events, and breathing in that pollution is going to be hard on everyone's lungs," Kastor said.
Physicians advising the U.S. Olympic team have been to Beijing three times in the last two years, to measure pollution levels. They have also visited the start of the marathon route in Tiananmen Square. Each time, they told ABC News that the readings were "awful."
Chinese doctor Pan Xiaochuan said athletes may experience a range of symptoms, from coughing and shortness of breath, to asthma attacks and serious heart problems.
Beijing officials hope that last minute measures, such as restricting traffic in the weeks leading up to the games, will be enough to clear the air.
If not, the international Olympic committee has said it may have to reschedule certain events — but that may upset finely tuned training regimens for many athletes.
"I really believe that China is looking at this as an opportunity to really set a great stage for themselves on the world level, and they have enough time now that they can be able to clean the air up for the athletes," said Kastor.
Kastor and a slew of competitors from other countries plan to wait until the very last minute to arrive in Beijing, thereby minimizing exposure to any foul air.
The Associated Press contributed to this report.