No abstract

No abstract

Soil samples from 95 gardens and leaf vegetables from 33 gardens in an approximately 3 km(2) area of downtown Washington, DC were analyzed for Pb, Cd, Cu, and Zn. The mean soil Pb was 680 μg/g with a range of 40-5300 μg/g. Soil Pb values in this sample were considerably higher than those previously found for a sample of 70 gardens distributed throughout the city. In the downtown sample, 46% of the soil Pb values were above 500 μg/g and 17% were above 1000 μg/g. Soil Pb levels were found to be higher near the house than away from the house, a pattern that was also evident, though less pronounced, for Zn and Cd. Lead-based exterior paint was identified as the most likely source of soil Pb in several cases. The mean leaf vegetable Pb was 6.4 μg/g dry weight, a small but significant difference from the mean value of 4.5 μg/g obtained from the city-wide sample of 38 gardens.

Dihydrogen phosphite ion, H2P03-, is not oxidized by HCrOr at pH 4 but does form an anhydride, (13) G. P. Haight, Jr., F. Smentowski, M. Rose, and C. Heller, J. Am. Chem. Soc" in press.of various preequilibria involving protons by substituting ethyl groups to form (EtO)3P:, (EtO)2P(=0)H, and (Et0)2P(=0)Et, and studying their oxidation by HCrOr.

No abstract