Abstract
The nature and composition of the eolian dust falling in the coastal area north of Jeddah, on the west coast of Saudi Arabia, were investigated over a period of 6 mo (Dec. 1981-May 1982). Considerable variation exists in the average daily fallout of the dust, from a minimum of 0.023 g/m super(2) /day in Feb. to a maximum of 0.061 g/m super(2) /day in Jan. The falling dust is characterized by a kaolinite-rich clay mineral assemblage except in April, during which period montmorillonite-dominant dust has been noticed. The average concentrations of heavy metals in the dust are significantly higher than those present in the nearshore sediments of Jeddah. Cadmium, which is highly concentrated in the dust, has probably been contributed by the cement industry and the intensified oil combustion in Jeddah. Although the falling dust at present appears to be a minor hazard, southerly winds can enhance the Cd contents in the dust and might damage the coastal ecosystem.