Toxicity of Airborne Metals

Health effects associated with the inhalation of airborne metals have been the subject of intense interest since the early days of pharmacology and toxicology. Many metals are ubiquitous in the environment, having multiple sources and routes of exposure. Metals represent the ultimate form of persistent environmental pollutants because they are chemically and biologically indestructible. The respiratory system is one of the primary target sites for metal toxicity. Inhalation exposure becomes critical when one considers that the mammalian respiratory system must not only maintain life by the exchange of gases but also perform a number of essential nonrespiratory functions such as the maintenance of an active immune system, metabolism of biologically active substances, and the clearance of viable and nonviable particles from the lung. The primary purpose of this article is to provide public health officials, physicians, toxicologists, and other interested individuals and groups with an overall perspective of the major components that comprise the respiratory toxicology of airborne metals.