Abstract
The respiratory tract is endowed with an interlocking array of nonspecific and specific defense mechanisms which protect it from the effects of inhaled microbes and toxicants, and reduce the risk of absorption of materials into the bloodstream, with subsequent systemic translocation. Ambient acids may compromise these defenses, perhaps providing a link between exposure and development of chronic and acute pulmonary disease. This paper reviews the effects of inhaled acids upon the nonspecific clearance system of the lungs.