Aerosol composition of urban and desert origin in the eastern Mediterranean.

Monthly dustfall samples collected in 16 sites in the Tel-Aviv urban areas, as well as those collected in 10 rural sites in Israel during several years of measurements, were analyzed for their physical properties and chemical content. Although dustfall measurements represent a very simple and crude technique the analysis of the data provides some very interesting conclusions: (a) The southwest part of Israel, which is scarcely populated, suffers from high dustfall values due to dust storm blowing from the Sahara and other arid lands to the east Mediterranean during the spring. (b) On an annual basis the natural dustfall of dust storms origin amounts to 25 to 30% of the Tel-Aviv residential area deposition or 3 to 4 tonne km mo. (c) Mapping of dustfall data within an urban region reflects fairly well the main industrial and commercial activities within the city. (d) In residential areas the inorganic water insoluble fraction of the dust is contributed by natural sources, while the organic fraction is mostly of anthropogenic origin. The inorganic water soluble fraction is spread in a uniform pattern within the city. [ABSTRACT FROM AUTHOR]