The 500-Meter Wheeze

Will air pollution affect the athletes at the 2008 Olympics in Beijing?

Olympic runners

Some events in the 2008 Summer Games may have to be postponed by a day or two if air pollution in Beijing is excessive, the International Olympic Committee said on Thursday. How will all this pollution affect the Olympic athletes?

Scientists haven’t done enough research to be sure, but it could make it impossible to break any world records. An athlete must breathe in a large amount of air during a competition—more than 20 times the amount inhaled by a normal person at rest. In Beijing, that means the athlete will be getting a super-sized dose of ozone and fine particulates, which can make respiration more difficult and reduce the amount of oxygen that gets to the muscles. (Other pollutants, like nitrogen dioxide, carbon monoxide, and sulfur dioxide also have negative health effects.) To make matters worse, some people are more sensitive to air quality than others, so there wouldn’t even be a level playing field, just because the contenders are all breathing the same pollutants. And since hundredths of seconds in performance can separate a gold medalist from the bronze, every breath counts.

Ozone, which comes mainly from car emissions, causes the smooth muscles surrounding a person’s airways to constrict. The World Health Organization suggests a maximum safe level of 60 parts per billion averaged over eight hours; at 100 ppb, the airways of healthy, nonasthmatic people will constrict by up to 20 percent, leading to lower oxygen levels in the blood. Meanwhile, some scientists believe the air in Beijing may at times contain up to five times the WHO limit, or as much as a heavily trafficked road in the middle of the afternoon on a sunny day.

It is possible to develop a tolerance to ozone over just a few days, but that doesn’t mean athletes should spend extra time training in Beijing. In fact, Olympics coaches advise competitors against arriving too early and recommend wearing activated carbon filtration masks. That’s partly because inhaling the tiny particulates in the air can have a cumulative negative effect on your physical performance. One study, to be published by the Journal of Strength and Conditioning Research, tested college athletes with six-minute bike rides in two environments—one with very little pollution, and one with quite a bit. (The air in the more polluted conditions contained 350,000 particles per cubic centimeter, the equivalent of a busy highway.) Then each group was asked to take another bike ride three days later in the same environment. Researchers found that heart rates didn’t vary too much from one ride to the next, but subjects in the high-pollution conditions had 5 percent less power on the second test. The study’s authors believe these students breathed in pollutants in the first high-particulate ride and started to develop inflammation in their lungs as a result. Three days later, they had a harder time pedaling.

Even though Olympic athletes are in superb physical shape, many of them also have some form of asthma, which can be triggered by poor air quality. A tenth of the general population has asthma, but 15 percent of athletes surveyed in the 1996 Summer Games had been previously diagnosed with the condition. Winter competitors have it worse: More than 60 percent of Nordic competitors at Nagano in 1998, for instance, had either been diagnosed with or had taken medication for asthma. These athletes have to follow International Olympic Committee procedures to show they need the meds, otherwise they might be charged with doping.

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