Geospatial analysis and assessment of garden soil contamination in New York City

Elevated trace metal concentrations, in particular, lead (Pb), are prevalent in urban soils and it is one of the main hurdles for urban agriculture. The growing popularity of gardening in urban areas could also mean increased public health risk. In this study, the spatial distribution of Pb in New York City gardens was analyzed and visualized by Geographic Information System (GIS) tools. Pollution level and ecological risks of gardens and overall New York City (NYC) were evaluated with different indices. The degree of the contamination factors was ranked as follows: Pb >Cu > Zn > Cr>As>Ni>Cd. The single ecological risk index and potential ecological index indicated that Pb had moderate to significantly high risk to the local garden ecosystems. Based on the pollution load index, soil quality of the majority of NYC gardens were characterized as polluted. Geostatistical, geoprocessing, and spatial tools were used to create color-coded maps to support decision making related to gardening and to estimate potential human health risks from gardening, living, or working in/or near these gardens. These findings have important implications for the development of pollution prevention and mitigation strategies to reduce public health risk from garden soil trace metal contamination.