Gardening on brownfields sites: evaluating trace element transfer from soil to plants and their transformations in soils.

Tens of thousands of brownfields (abandoned or underutilized properties where known or potential environmental issues are an obstacle to redevelopment) can be found in cities, towns, and rural areas across the USA. Our work has focused, in part, on the conversion of brownfields to garden areas and is motivated by the increasing interest in locally produced foods. Challenges of converting brownfields to community gardening sites will be discussed using one newly established urban community garden site located in Kansas City as an example. This site had mildly elevated levels of lead (Pb) and some detectable levels of dichlorodiphenyltrichloroethane/ dichlorodiphenyldichloroethylene (DDT/DDE). Suitable safety/corrective measures were suggested and implemented after thorough evaluation of soil properties. Measures focused on reducing both direct (soil-human) and indirect (soil-plant-human) exposure of Pb and/or DDT/DDE to the gardeners and their children. In addition, field test plots were established within the community garden and three crop types with three very different growth and contaminant uptake patterns were planted. Effectiveness of selected site-specific soil amendments to reduce bioavailability of Pb will be evaluated. Different methodologies will be utilized throughout the project to understand the significance of potential soil-plant-human exposure pathway of contaminants while gardening on mildly contaminated sites. Efforts will be made to understand relationships between key soil properties and contaminant bioavailability.