There was something in the air at the recent Hong Kong Marathon, and it wasn't the sweet smell of success.

With air pollution at high levels, 40,000 runners participated in the Feb. 12 event, most of them in the 10K (6.2 mile) race. But 9,116 ran the half-marathon (13.1 miles), and another 3,184 went the full 26.2-mile marathon distance on a day when the air pollution index reportedly reached 149 on a scale of zero to 500 - a level at which local authorities usually issue health warnings for those with heart or respiratory illnesses.

What happened was what many would consider inevitable in those conditions: A 53-year-old runner, reportedly an asthmatic, collapsed during the race and later died. Another 19 participants in the race were also reported to have collapsed, including one 33-year-old man who was hospitalized in critical condition.

Responding to post-race criticisms that the race should not have been held on such a smoggy day, officials said that at the start of the race (8:15 a.m.) the pollution readings were at 100, a level considered high but not severe enough to affect healthy individuals. The index is calculated by measuring concentrations of five pollutants - including ozone, carbon monoxide and nitrogen dioxide - in the air at a given time.

Smog or high ozone or pollution levels are not an issue for the Long Island Marathon - held the first Sunday in May. "We've never had a problem with air quality," says Dr. Edward Fryman, medical director for the event since the early 1980s. As for outdoor exercise in general, Fryman says, "I don't think that air quality should be a concern for Long Islanders. I find if I run and pass a truck and suck in fumes, I'm not happy about that. But it's not an excuse not to run."

Besides, he notes, there are alternatives here to running alongside Jericho or Hempstead turnpikes at rush hour. "There are really nice bike paths and greenbelt trails all over Long Island. Those are wonderful places to run or walk in, and the air quality is great. The only thing you have to be concerned about there is ticks."

Cancelation idea a surprise

No one disagrees that Hong Kong is a polluted city, with most of it coming from the growing number of factories in the neighboring Pearl River Delta of southern China. "The air pollution here is bad and has been getting progressively worse in the last 10 years," says Gillian Castka, a British expatriate and elite runner. The smoggy conditions haven't kept her from running, however: "I've been averaging about 40 to 50 miles per week for the past 15 years, and I just get on with it," she said in an e-mail.

Still, the deaths and injuries attributed to poor air quality - and the suggestion of canceling a race for that reason - caught many Western marathon officials by surprise.

"I've heard of postponements and cancellations due to weather ... lightning ... or other acts of God, but not this," said Jack Fleming, spokesman for the Boston Athletic Association, organizers of the Boston Marathon. That race, which will be held for the 110th time April 17, is the world's oldest marathon.

When it was first run there were concerns participants might die in Boston, but the more likely culprits would have been the cigarettes smoked by many runners of that era, the strychnine-laced drinks some took as performance aids, or the trolleys that crossed the marathon route at several points. Unless you counted the clouds of dust kicked up by runners on the dirt roads, air pollution in the 1890s was not an issue.

Should it be now?

Despite what happened in Hong Kong, experts doubt there is a link between deaths and injuries in the marathon and air quality. "I think it had nothing to do with the smog," says Dr. Robert Sallis, a physician in Rancho Cucamonga, Calif., who is also vice president of the American College of Sports Medicine. "It's funny how critics jump right on that, however."

Asthma study of athletes

Sallis has published a number of studies about the effects of air quality on runners and other athletes. One, published in May 2005 in the journal Medicine & Science in Sports & Exercise, analyzed rates of asthma and allergy attacks among college athletes who grew up in nonsmoggy areas but attended schools and competed in smoggy areas.

Among the 464 athletes (all competing in outdoor sports) followed in the study, Sallis and his colleagues found that "very few" developed asthma during their four years of sports competition in areas with high levels of pollution. Based on this data, he concluded, "pollution levels may not be as strong a trigger for asthma and allergy as has traditionally been thought."

Sallis is quick to point out that he does not consider pollution acceptable; he just doesn't want to see it used as an excuse not to run, walk or engage in healthy outdoor exercise.

"I think the benefits of exercise and running so outweigh the small potential risks of air pollution," he says. "I would worry that even talking about this would discourage some overweight guy with diabetes to get up and do something that would bring far more benefits."

In other words, remaining sedentary in a polluted area is more dangerous to your health than running in it.

Some should be cautious

Of course, there are commonsense precautions that should be taken, especially among those who suffer from asthma: "If you're a bad asthmatic, you might want to exercise indoors on those days when it's really smoggy," Sallis says. "But the vast majority of people have so much more to worry about than this."

So what explains the deaths and injuries in the Hong Kong race?

"Any time you get 40,000 people doing the same thing in the same place you would expect that problems can occur," says Richard Castka, Gillian's husband and publisher of a running magazine in Hong Kong. "One big problem we now have is that [the Hong Kong Marathon] has taken on a sort of cult status in which lots of people feel they simply have to take part. Many do not prepare properly or wear the right shoes and apparel. Some have no idea what it's like to walk [a half-marathon], let alone run it. They enter the half, thinking it's not too far and then have to start walking after 3 kilometers."

Or, as one asthmatic runner said on a Hong Kong running Web site: "I wish I could blame my slower-than-expected time on the air quality, but I think it was just that I wasn't on form that day."

Keeping ahead of asthma

An estimated 20 million Americans suffer from asthma, a disease in which the air passages in the lungs become narrow or blocked by mucus or a muscle spasm. An estimated 70 percent to 90 percent of them have exercise-induced asthma.

Still, having asthma is not a reason not to enjoy the proven benefits of physical activity. "Do not let [asthma] keep you from leading an active life or from achieving your athletic dreams," the Asthma and Allergy Foundation of America writes in its guidelines.

A women's health and fitness Web site, womenfitness.net, offers these suggestions on how to make workouts more comfortable for asthmatics:

Consult with your physician before beginning an exercise program.

Be particularly diligent when it comes to intensity: Perform a 5- to 10-minute warm-up before vigorous exercise; build up gradually for the first 10 to 15 minutes of the workout, and cool down for 10 to 30 minutes afterward.

Some activities are easier than others: In part because the air of the typical pool is humid, swimming is especially recommended, but it's worth noting that many asthmatics also run - an activity often considered a trigger for asthma attacks.

Take precautions when exercising in cold climates or when pollen and pollutant levels are high. Cold, dry air greatly increases the risk of an asthma episode, so on such days it might be wise to exercise indoors or breathe through a scarf or mask.

For more information and tips on asthma and exercise, visit www.aaaai.org, Web site of the American Academy of Allergy, Asthma & Immunology.

Source: http://www.newsday.com/news/health/ny-hsnutrition4652716mar07,0,1380996.story?coll=ny-health-print