Ahstnet X-ray diffraction panems of equimolecular concentrated aqueous solutions of yttrium chloride and bromide have been investigated from s = 0.4 A-' up to s = 15 .&-I, An assumed coordination of eight water molecules around each ymium cation, at a distauce of 2.36 A. reproduces the intensity at high s values in agreement with the values obtained by some of the present authors from WAFS experiments. Narrow interference maxima at s = (4n sin0)jX E 0.9 A-' may be interpreted as the existence of a local order of the hydrated yttrium cations surrounded by anions and free water molecules. Structural models with and without close packing of lhe hydrated cations were built to simulate fhat local order.

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Chemotaxis and nitroblue tetrazolium reduction were measured in peripheral blood neutrophils of workers occupationally exposed to lead. These two neutrophil functions were significantly reduced, as compared to controls, even in those workers with blood lead levels and urinary delta-aminolevulinic acid (ALA-U) concentrations below the currently accepted biological limit values of 60 micrograms/dl and 6 mg/l, respectively. The immunosuppressive effects of relatively low level lead absorption suggests that immune dysfunction may be a sensitive indicator of lead exposure.

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