Soil samples from 4 defined city zones of Nanjing were randomly collec ted at 0—5 cm and 5—20 cm intervals and size fractions of soil particles were separated from undisturbed bulk soils by low energy dispersion procedure. The to tal contents of Cu and Pb in the different particle size fractions of the urban soils were analyzed by HNO3-HF-HClO4 digestion and flame atomic absorption spect rophotometer determination. The total content of Cu and Pb in soil particle size fractions varied with their size and with city zones as well. Both the content and variation with the size fractions of Pb was bigger than of Cu supporting our previous finding that there was Pb pollution to different degrees in the urban soils although the two elements were generally enriched in clay-sized fraction. Contaminated Pb tended to be preferentially enriched in the size fraction of 200 0—250 μm and clay-sized fraction. While the size fractions of the soils from n ewly developed and preserved area contained smaller amount of Cu and Pb, the par titioning of them in coarse and fine particle size fractions were insignificant compared to that from inner residence and commercial area. The very high Pb leve l over 150 mg/kg of the fine particle fractions from the soils of the inner city could be a cause of high blood Pb level reported of children from the city as a cute exposure to Pb of fine particles of the urban soil might occur by soil inge stion and inhalation by young children. Thus, much attention should be paid to t he partitioning of toxic metals in fine soil particles of the urban soils and co untermeasures against high health risk of Pb exposure by soil ingestion and dust inhalation should be practiced against the health problem of blood Pb for young children from the cities.
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