Dissertation Research: The effect of human management and soil properties on heavy metal content of Los Angeles Community Garden soils

University Of California-Riverside, Riverside CA

Investigators

Abstract

Community gardens are hotspots of interactions between humans and the environment. Little is known about biogeochemical cycles or metal accumulation in these constructed ecosystems, both of which can impact the health of crops and the people who consume them. These knowledge gaps will be addressed by investigating the impact of management, land use legacy, and neighborhood on soil and crop metal availability in Los Angeles community gardens. Soils will be collected in 12 gardens from cultivated, uncultivated, and surrounding locations and analyzed for pH and concentrations of nutrients, organic matter, and 29 metals. Leafy and root vegetable samples will be collected from each garden and tested for metal concentrations to determine bioavailability and human exposure risk. Gardeners will also be interviewed about their management activities. A multiple regression framework will be used to determine if gardening practices or neighborhood characteristics (e.g., freeway proximity, previous land use) can be used to predict soil metal concentrations and bioavailability at gardener, garden, and regional scales. Data pertaining to management influence on metal availability will be of use to garden managers and city planning departments. The metal content of urban soils and crops in Los Angeles has important human health implications. Reports on metal content of garden soils and crops, as well as educational materials on soil testing, will be presented to garden managers, participants, and supporting non-profit agencies. These activities will provide access to scientific resources for minority populations.