As environmentalists have pointed out, it can be as dangerous to be outdoors behind a city bus -- walking or bicycling -- as it is to be in front of one. All the exhaust and smoke -- even when they have been reduced by clean-air technology -- can damage a person's health. The dangers of urban air pollution are of special concern to those who exercise by running, bicycling or skating. These individuals, while trying to help their bodies through exercise, should take care that they do not harm themselves through exposure to air pollution.
Dr. Ronald Crystal, chief of pulmonary medicine and critical care at NewYork-Presbyterian Hospital/Weill Cornell Medical Center, says that air pollution is definitely a problem for those who work out in the city. The main culprits are ozone, fine particulate matter, and carbon monoxide, he says. These pollutants irritate the lungs and respiratory system, and can exacerbate the problems of individuals with underlying disease -- such as asthma, bronchitis, emphysema, or cardiopulmonary maladies.