Cellular Specific Toxicity in the Lung

The architectural structure of the lung is designed to provide and protect a vast surface area within the chest cavity which allows the effective exchange of respired gases with the bloodstream. This means that the lung has numerous cell types with specific functions and when the cell types in the blood are taken into consideration, over forty individual cell types have been identified (Sorokin, 1970). Since the total cardiac output passes through the lung, the lung can be exposed to toxic xenobiotic compounds and their metabolites present in the blood. The lung is also exposed to gases, vapours and particles (if small enough) present in the inspired air. Even toxins present at very low concentrations in the atmosphere may present a risk to the lung, especially when one considers that the adult human lung respires approximately three tons of air per year (Mustafa and Tierney, 1978).