children have a higher resting metabolic rate and rate of oxygen
consumption per unit body weight than adults because they have a larger surface area per
unit body weight and because they are growing rapidly. Therefore, their exposure to any air
pollutant may be greater.
In addition to an increased need for oxygen relative to their size, children have narrower
airways than do adults. Thus, irritation caused by air pollution that would produce only a
slight response in an adult can result in potentially significant obstruction in the airways of a child