Mean fresh weight analyte concentrations in field samples by urban/urban farms, with comparisons to prior estimates.

Mean fresh weight analyte concentrations by urban/rural farm, with standard error (SE). Since there was only one market sample from urban farms, market samples are not included in means. Estimates from the current study are compared against prior estimates from the Safe Urban Harvests (SUH) study (27) and the USDA FoodData Central database entry for raw kale (NDB number 11233) (2). The SUH study included kale samples from urban farms and community gardens in Baltimore City (N = 25) and “non-urban” results that included conventional and organic kale samples from grocery stores, and samples from farmers market vendors from outside the city (N = 32). Lutein and zeaxanthin concentrations were combined for this table so they could be compared to USDA values. Chromium was not speciated between hexavalent chromium (a carcinogen) and trivalent chromium (an essential nutrient).