| Mineral aerosol： Connections to climate and human health |
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| 作者姓名： | Richard Arimoto |
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| 作者单位： | Carlsbad Environmental Monitoring ＆ Research Center, NM State University, USA |
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| 摘 要： | Mineral dust is a major component of the global aerosol, and the importance of dust for regional climate and biogeochemical cycles has become increasingly apparent. By scattering and absorbing radiant energy and through their effects on clouds, dust and other aerosol particles can cause climatic effects that affect ecosystem function and human health. Iron oxide minerals in the atmosphere are especially important in this regard because they absorb solar radiation and are involved in redox reactions. Furthermore, dust particles that settle out of the atmosphere provide nutrients, including iron, to marine ecosystems and other nutrients to terrestrial ecosystems. New technologies have shown that dust reacts in complex ways with other atmospheric constituents; indeed, this is one of the major revelations of recent dust research. Dust and other substances commonly occur in the same air parcels, but bulk chemical methods do not show whether the particles are internally mixed （multiple components mixed in single particles） or externally mixed （admixtures of different particles）. Electron beam techniques have shown internal mixtures of dust and black carbon, but the implications of this for climate forcing are still unresolved. Studies conducted with an aerosol time-of-flight mass spectrometer suggest preferential reactions between dust, sulfur and nitrogen oxides, and chlorine. These reactions have important implications for particle formation and solubility, and for the particles＇ health effects. The activity of radionuclides, including Pu, co-vary with atmospheric dust loads, and while this is not a serious health concern, the emerging view is that pure dust is rarely sampled. While dust can affect ecosystems through climate, the production of dust also is influenced by humans, especially land-use practices that affect vegetative cover. Indeed, the issue of the relative importance of natural vs. anthropogenically-driven changes in dust budgets remains a subject of debate although several recent studies indicate natural variability dominates.
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| 关 键 词： | 气溶胶 环境污染 气候 生物地球化学 |
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