AN OVERVIEW OF THE IMPACTS OF MINERAL DUST ON HUMAN HEALTH

In many locations the particulates in ambient dust are dominated by naturally occurring minerals. These minerals have been linked to, or speculated to be the cause of, a variety of health issues. Inhaled mineral dusts such as asbestos and crystalline silica can trigger toxicity as they accumulate and persist for many decades in the lungs or other parts of the body; these dusts are associated with fibroses of the lungs (asbestosis, silicosis), lung cancers, and, in the case of asbestos, mesothelioma cancer. Other mineral dusts are believed to be a source of toxicity because they contain soluble heavy metals or metalloids; examples include soluble iron sulfates in coal dust (thought to contribute to coal workers' pneumoconiosis), and arsenic-rich dusts from dry lake beds such as Owens Lake, California. Still other mineral dusts can be acutely bioreactive and cause tissue damage in the respiratory tract, such as the highly alkaline dusts generated by the World Trade Center collapse. Recent studies have indicated that minerals may act as a protective host for a variety of pathogens helping them survive global transport in dust clouds. The morphology, crystalline structure, and chemical composition are critical parameters in determining the potential toxicity of the minerals; this information may be essential for proper toxicologic and risk assessments.