No athlete pulled out of the 2002 Winter Olympic Games in Utah because of bad air quality. The government didn't order vehicles removed from the road. Factories didn't close and construction work didn't stop.
That's all happening in Beijing, where the city's deputy director of its Environmental Protection Bureau, Du Shaozhong, felt compelled to guarantee "good air quality" for the Summer Games, which begin Friday. China has been taking extraordinary steps to clean up its air, shutting down traffic and moving factories out of urban centers.
But worries, like the pollution itself, linger.
The biggest short-term impacts on air quality are emissions from sources like vehicles and factories and how stagnant weather conditions are, said C. Arden Pope, Brigham Young University epidemiologist, professor of economics and a world-renowned expert on the health effects of pollution. Chinese officials are trying to limit emissions and undoubtedly hope the weather will do its part. But it's hard to predict, Pope said.
It is not known what, if any, long-term effects short-term exposure to possibly severe pollution will have on healthy athletes, said Dr. Richard Kanner, a pulmonologist at University Hospital. "It's not ethical to do a study getting healthy young athletes to run through severe pollution," he said. Studies in polluted chambers aren't comparable.
Athletes who perform at outdoor venues will experience the worst of whatever's in the air, said Dr. Max Testa, exercise and pulmonary specialist at The Orthopedic Specialty Hospital. And because of the exertion required, they'll breathe through their mouths, losing the nose's filtering ability.
Adults at rest pump 12 liters of air in and out each minute. Athletes in competition breathe 200 liters in and out in a minute, he said. But while all the athletes in a given event will process about the same volume of air, they won't be equally disadvantaged by pollution. "Some are more sensitive to pollution than others, and you can't train for polluted air," Testa said.
He doubts that short-term exposure from the Games will turn into long-term damage. "The only long-term effect may be they don't win a medal," he said. "It definitely could impact performance."
If he were coaching the athletes, he said, he'd tell them to "get there at the last minute and use a mask before competition. Breathe unfiltered air just for the race."
Some of the symptoms related to pollution include chronic irritation, coughing, wheezing and itching eyes, he said.
The Games themselves could provide a great opportunity to study health effects, Kanner said. "If it's messy, I hope someone does measurements, to follow the athletes and see what happens. I suspect markers of inflammation will appear. Any harm, though, may not show up for 20 years. It's not a simple thing."
Kanner said bad air may initially trigger bronchospasms. That they'll stop over time may not be good. Bronchospasm may keep ozone from going deep into the lung. "It causes an oxidative reaction, probably the reason we age and fall apart over the years. It's like smoking. In a healthy young athlete, you might see some change in pulmonary function before and after. It could affect performance."
Air quality can change quickly, as Utah's Olympic Games show. The day before the Feb. 8, 2002, opening ceremonies, the inversion had cast a milky haze over the Salt Lake Valley.
Measurements were high for PM2.5, ultrafine particulates from the soot from chimneys and industrial stacks and vehicle exhaust. A PM2.5 reading above 35 is "unhealthy," but the number soared to 89 that day, according to Division of Air Quality records.
"It was a big concern as we were going into the opening ceremonies," said Bryce Bird, Utah DAQ planning branch manager.
During months of planning, strategies were devised to encourage less idling time for buses taking fans and media between Olympic venues. Businesses were asked to reduce emissions wherever possible. People were encouraged to commute during off hours. None of it seemed to have a noticeable impact until Mother Nature intervened.
"We had a front come through and clear everything out," Bird said.
When the Games began in Utah, the Salt Lake Valley's PM2.5 reading was a mere 7.5. Its peak during the two weeks would be 57 on Feb. 11. But even that day in 2002 when the PM2.5 was 89 would be just an average day in Beijing, where average pollution is about 10 times higher than it is in Utah, said DAQ toxicologist Steve Packham. He quoted a 2007 scientific journal that recorded a record-high PM2.5 reading for Beijing at 216. The highest-ever in Utah was recorded in Logan a few years ago at 135.
The risk for athletes in Beijing, he said, is that lung health will suffer permanent damage, such as developing a sensitivity to allergens, exacerbating symptoms of asthma or inflaming lung tissue the common denominator for causing some respiratory diseases.
But the decision to compete or not belongs to the athletes, he said.