EXAMINING TRACE ELEMENT CONCENTRATIONS IN KALE FROM TUCSON: COMMUNITY GARDENS VS. GROCERY STORES

Abstract

This project set out to examine trace element concentrations in kale (part of the Brassica oleracea family) from two sources in Tucson, Arizona: community gardens and grocery stores. The study evaluated whether the vegetable accumulates different concentrations of trace metals Al, Cr, Ni, Cu, Zn, As, Se, Cd, Pb, and Mo in urban settings than it does at commercial farm locations. Median grocery concentrations exceeded median garden concentrations for all metals except Zn, Pb, and Mo. Using an exposure assessment, none of the samples analyzed had concentrations that reach EPA reference doses within one serving, but concentrations of Mo, Se, and Cd reached EPA reference doses (0.005 mg/kg/day, 0.0003 mg/kg/day, and 0.001 mg/kg/day, respectively) within five-six servings.