Trace Metal Contamination in New York City Garden Soils

Urban gardening, urban agriculture, and urban farming provide healthy food and promote environmental, social, cultural, and educational benefits. However, urban soil is a natural sink for contaminants derived mainly from historical anthropogenic activities. This article reports a summary of trace metal concentrations (Cr, Co, Ni, Cu, Zn, As, Cd, and Pb) of 1,652 garden soil samples from 904 gardens in New York City. Based on the Soil Cleanup Objective (SCO) criteria developed by New York State Department of Environmental Conservation (6 NYCRR Part 375). Many of the soils analyzed exceeded the limits for Pb, Cr, As, and Cd levels. Higher percentages of home gardens are contaminated than community gardens. When accounting for Pb and As levels, about 21% of the community garden samples and 71% of the home garden samples exceed respective SCO limits. Among all home and community garden samples, less than 3% meet the criteria for unrestricted use when all trace metals are considered. There are controversies on the appropriateness of SCO criteria for urban gardening situations. Consistent soil trace metal guidelines pertaining to gardening need to be developed. Expanded soil screening, greater public awareness, and education are urgently needed to ensure safe and successful urban agriculture.