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.

KEYWORDS:

• Heavy metals
• soil contamination
• vegetable contamination
• urban gardens
• plant uptake
• health risk
• inductively coupled plasma mass spectrometry

Acknowledgments

The authors thank the Philadelphia-region community gardens who allowed us to test their soil and produce.

Disclosure statement

No potential conflict of interest was reported by the authors.

Data availability statement

The authors confirm that the data supporting the findings of this study are available within the article and its supplementary materials. Raw data can be provided upon reasonable request.

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/26395940.2023.2209283

Additional information

Funding

This work was supported by Villanova University’s Falvey Memorial Library Scholarship Open Access Reserve (SOAR) Fund [N/A]. This work was also supported by the National Science Foundation Division of Biological Infrastructure Major Research Instrumentation Grant [1726705].