Growing food on commercial or abandoned lots is a wonderful way to find space for gardening in the city. One concern, however, is the potential for soil contaminants, such as lead, that could be present in the soil. The bad news is that human contact with toxic soil can present a health risk. The good news is that vegetables do not typically uptake these contaminants into their tissues, so the risk is easily reduced by limiting human exposure to the soil itself. And toxic soil can be repaired.
The links below provide guidelines for gardening in potentially toxic spaces and soil remediation:
Urban Gardens and Soil Contaminants by Minnesota Institute for Sustainable Agriculture (MISA)
Reusing Potentially Contaminated Landscapes: Growing Gardens in Urban Soils published by the Environmental Protection Agency (EPA)