Structure of the Respiratory System

One of the reasons that air pollution is such a threat to human health it that humans have no choice over the air that they breathe. Thus in our homes, outdoors, and in workplaces, we often breathe air which is not as clean as we would prefer. The average adult breathes approximately 10,000 to 12,000 liters of air each day of life. Individuals who exercise frequently or have jobs that involve strenuous activity breathe a much greater volume of air. Inhalation is the major route of entry into the body for toxic materials. Given the volume of air inhaled, it is not surprising that respiratory illnesses are the fourth most common illness or that occupational lung disease is the most common occupational disease. In order to prepare the reader for discussions of air pollutant-respiratory system interactions, this chapter will give a brief summary of the structure of the respiratory system. The structure of the respiratory system largely determines its function. It is recommended that the reader consult a respiratory system textbook if more detail is desired.