ABSTRACT
Pollutant injury to the lower respiratory tree, including the trachea, the bronchi, and the alveoli, may be a little different from injury to other organs where direct contact with pollutants does not occur. Principles involved in pollutant damage to the respiratory tree include total body load, the adaptation phenomenon, bipolarity, and biochemical individuality of response, as well as the spreading phenomenon and switch phenomenon. Pollutant-induced injury to the nervous system of the respiratory tree can occur in the brain and in the respiratory center as well as in the spinal cord, anterior horn cells, peripheral nerves, and/or the autonomic nervous system (ANS) and neuroendocrine receptors. Early pollutant injury to the lung may be extremely subtle and imperceptible because of the massive number of alveoli present. The airway epithelium plays a key role in the induction of inflammation of the mucosa following pollutant exposure(s) in the chemically sensitive individual.
