Anticipating the health risks of atmospheric dust on the basis of dust-source settings

Dust is emitted from diverse settings. Geologic, hydrologic, ecologic, land-use, and climatic conditions interact in these settings to promote or suppress dust emission and to determine dust composition. New knowledge about dust sources, conditions of dust emission, and composition of dust can now be applied to evaluate potentially adverse effects of dust on human health. Moreover, we can commonly track dust plumes from these sources into populated areas using satellite images and predict dust emission and pathways using meteorologically-based computer simulations of wind directions and intensities.

The common potential health hazards from dust consist of (1) particulate matter (PM, mostly <10 micrometers in diameter); (2) specific minerals (e.g., asbestiform types); (3) bioavailable metals and metalloids (M); (4) pathogens (P); and (5) herbicides/pesticides (H/P). Examples of dust sources that bear on potential health hazards include sparsely vegetated arid lands (PM and P hazards); evaporative dry lakes (M hazards in saline-mineral dusts); agricultural and grazed landscapes (PM and H/P), and burned areas (PM).

The many avenues for future work range from forecasting dust emission using drought-prediction maps (based on climate and soil moisture models) to monitoring affected populations for suspected dust-composition hazards. We can also anticipate dust emission and composition from new sources on the basis of land-management policies and ensuing human actions. As one example, the planned drop in water level at Salton Sea (southern California) will likely lead to greater dust emission, with potential PM, P, M, and H/P effects on nearby communities.