title: Metals in downtown Washington, DC gardens.
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.
authors.affiliation: Environmental Science Department and Agricultural Experiment Station, University of the District of Columbia, 20008, Washington, DC.
authors.forename: J R
authors.initials: JR
authors.lastname: Preer
authors.forename: J O
authors.initials: JO
authors.lastname: Akintoye
authors.forename: M L
authors.initials: ML
authors.lastname: Martin