Assessment of heavy metal contamination in soil and produce of Philadelphia community gardens

Abstract

Urban and ex-urban residents have been increasingly utilizing community gardens to supplement their diets, foster relationships with neighbors and learn new skills. Soils in urban-region community gardens, however, can be detrimental to human health if contaminated with metals. In this study, the soils of 20 Philadelphia-region community gardens (and produce from 6 gardens) were analyzed for heavy metal content (As, Cd, Cr, Co, Cu, Ni, Pb) to assess bioavailability, determine relationships with environmental and demographic variables and compare with published safe limits. About 58% of soil samples and 86% of produce samples were above their respective safe lead level. Metal concentrations in garden produce differed between produce types, with the highest concentrations of As, Cr, Co and Cu found in root and leafy vegetables and the lowest concentrations found in fruiting vegetables. Philadelphia-region community gardeners are exposed to unsafe levels of metals both from the soil and from consumed produce.