Assessment of Trace Metal in the District of Columbia Food Hub's Soil

Graduate #64
Discipline: Ecology Environmental and Earth Sciences
Subcategory: Pollution/Toxic Substances/Waste

Kailash Tilhoo - University of the District of Columbia
Co-Author(s): Mani Shehni Karam Zade, Sebhat Tefera, and Tolessa Deksissa, University of the District of Columbia

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The University of the District of Columbia (UDC) has many urban agricultural projects that provide a source of local food in the food desert neighborhoods of Washington, D.C. However, urban garden soil may be contaminated with trace metals such as lead and arsenic. Soil testing should help gardeners grow food safely in urban soils and determine if expensive measures to avoid trace metal exposure is necessary for their gardens. The objective of this study was to analyze soil trace metal levels at a number of UDC urban farms and at the UDC research farm in Beltsville, MD. The hypothesis was that lead and arsenic level of the UDC food hubs may exceed Environmental Protection Agency (EPA) guidelines. Total trace metals were measured using Inductive Couple Plasma Mass Spectrophotometer. Average soil lead level was found to be 22 mg/kg, which was significantly below the EPA residential clean-up standard of 400 mg/kg, while average arsenic level was 3.5 mg/kg, which exceeded the EPA soil screening guidelines of 0.41 mg/kg. This indicates that some parts of gardens in DC are contaminated with arsenic. Further study is required to determine cost-effective techniques for reducing exposure of gardeners to excessive Arsenic level in soil.

Not Submitted

Funder Acknowledgement(s): NIFA, NSF

Faculty Advisor: Tolessa Deksissa, tdeksissa@udc.edu

Role: Sample collection, sample preparation, data analysis and interpretation.