Methods for evaluating the lung in human subjects

The lung is frequently the target of environmental and systemic toxic exposures. A normal adult at rest takes in more than 7000 l of air daily (1). Gas exchange requires exposure of a surface area of approximately 80 m of the lung to this inhaled air (2). This makes the lung uniquely exposed to airborne toxins. In addition, the lung receives the entire cardiac output from the right side of the heart, which places it at risk for systemic toxins. Finally, specific metabolic reactions in the lung can lead to the uptake and concentration of a variety of toxins in the lung. As a result, toxic exposures are a frequent cause of lung disease. Evaluation of the lung, therefore, is highly relevant in toxicological studies.