If you were paying more attention during science class than I was, you know the air we breathe contains more than just oxygen. There are all sorts of gases in our air—some necessary for life and others that are deadly in certain doses.
By now, we all know that mother earth is horribly polluted. Every continent—with the exception of Antarctica—has unhealthy levels of air pollution. And even Antarctica, has a pronounced hole in the ozone layer which protects us.
But clearly, the citizens of the major cities are at greatest risk to the ill effects of air pollution. A random sampling of air in the major cities of the United States contains a dozen or more harmful pollutants. With each deep breath, we inhale many of these pollutants.
When you run or walk, we are at special risk because we are outside so much and breathing so deeply. How deeply? A runner moves eight to 10 times more air through the lungs than someone who is at rest on the couch.
Obviously, this isn’t a newsflash that air pollution is harmful to all life forms. The thick, noxious air of many of our big cities is a national calamity that effects millions of our citizens. It’s particularly bad during the summer in Austin when air quality is the worst.
Fortunately, our air quality isn’t nearly as bad as Los Angeles’ which annually has the greatest number of days when its air exceeds the pollution standard index. Actually, California leads the way with the most polluted cities in terms of ozone pollution. The five worst cities in America are LA, Visalia-Porterville, Bakersfield, Fresno and Sacramento. Houston and Dallas-Ft. Worth rank six and seven with the most unhealthful levels of air. But there are plenty of others that have air that is deemed “unhealthful” at least one a day week. (Austin and San Antonio don’t even rank in the top 25 (yeah us).
Although there are dozens of pollutants, a runner must be most concerned with four: carbon monoxide, oxides of nitrogen, sulfur and ozone. Carbon monoxide is—by far—the primary pollutant. It is tasteless, odorless and colorless. CO2 occurs mainly as a byproduct of the combination of fossil fuels, such as coal and gas, and is most prevalent near busy roads or highways and industrial areas. The more we drive, the more we pollute our air.
The other three are just as noxious. The family of gases containing nitrogen are varied and include, nitric acid which reacts with sunlight to form nitrogen dioxide, the pollutant which causes the yellow pall that suffocates many cities.
Oxides of sulfur work to foul the flavor of the air and give it that revolting taste. This is usually the result of combustion of fossil fuels.
Ozone is a little different. It is actually essential to life and occurs naturally in the upper reaches of the atmosphere to screen out harmful rays of sunlight. But as pollution has increased, a second layer of ozone has formed near the surface of the earth which, when inhaled, is harmful.
All these pollutants are often trapped near the ground and not enough fresh wind is available to disperse these pollutants. But the pollution levels vary greatly during a day.
Certainly the amount of pollution increases in big cities during prime commuting hours as more vehicles hit the roads, but also the sun intensifies the effects of pollution by stimulating secondary pollutants. So, as anyone who has lived in a major city knows all too well, as the sun rises and becomes more intense, the air becomes dirtier, stinkier and more lethal.
You don’t need a Pd. D. to know that bad air is a bad thing for runners and other life forms. Air pollutants irritate the tissues lining the air passages and lungs, resulting in an accumulation of fluid in the lungs and a reduction of the oxygen that gets delivered to them. This impacts runners with a wheezing and coughing, characteristic of asthmatics.
There’s no question that high concentrations of air pollution has all sorts of negative impacts on runners such as difficult breathing, increased coughing, irritated eyes and others. Pollution also results in a drop off in ability to run.
How detrimental is air pollution to your ability to run? Extremely. One study in New York City of healthy, non-smoking runners showed that just 30 minutes of running in particularly high areas of air pollution, was the equivalent (in terms of carbon monoxide) to smoking 20 cigarettes a day.
Making matters worse, air pollution can accumulate in a body exposed to it for longer periods. This can only have dangerous long-term effects as constant exposure to carbon monoxide is known to be a major factor in coronary heart disease.
Thus, it is absolutely crucial for runners living in major cities with known dangerous levels of air to take several precautions.
Here are some tips to minimize the effects:
1. Run early. Air pollution rises during the day so an early-morning runner is exposed to less pollution than someone running in the afternoon.
2. Avoid running near highways or busy roads. Air pollution is highest where the concentration of vehicles is highest.
3. If possible, run in a windy area. The winds disperse pollutants better.
4. Monitor daily pollution levels. If the air quality is especially unhealthy, either don’t run that day or run indoors on a treadmill.