干旱区生态环境知识资源中心

Transport of desert dust is often accepted as a migration of clay minerals having various size fractions. Smaller fractions are capable of achieving transcontinental or transoceanic transport via prevailing wind systems as well as going deep into respiratory system through inhalation. Dust and cloud interactions assisted by the action of bacterial excretion products can lead to alterations of desert-dust clay fraction within the cloud droplet, which result in the formation of reduced iron and some other essential micronutrient elements within the dust veil, provided there is sufficient solar-light intensity. Here we present on a daily basis a 6-month time series of air-quality measurements, precipitation data and number of patients applying hospitals having respiratory problems. The number of patients correlates with the air-quality deterioration associated with dust pulses, excepted during the precipitation-free season. We therefore tentatively assign this correlation to the effects of in-cloud bacterial interaction with dust, rather than to dust itself.