2015 GSA Annual Meeting in Baltimore, Maryland, USA (1-4 November 2015)

Paper No. 84-4
Presentation Time: 8:50 AM


GALLAGHER, Ciaran L., OETTGEN, Hannah L., OKHAI, Disha C. and BRABANDER, Daniel J., Geosciences, Wellesley College, 106 Central Street, Wellesley, MA 02481, cgallag3@wellesley.edu

Antique urban fruit cultivars, many of which grow in areas with elevated soil lead levels, are being re-discovered as a source of seasonal fresh fruit both for primary consumption and for canning and preserving. While previous research has focused on the consumption of traditional produce from the urban landscape, the risks associated with urban fruit consumption have not been formally evaluated. This concern has fostered our partnership with the League of Urban Canners (LUrC), an urban harvesting collective in the greater metro Boston area. Members of LUrC provided 166 samples of apples, peaches, cherries, and other fruit and herbs, which were frozen and labeled in the lab. A coded sample location map was created to assess the impacts of traffic and road size on measured fruit lead levels. Twenty-four urban and fifteen commercial fruit samples were dried in a commercially available fruit dehydrator, to mimic methods used by LUrC members in their home kitchens, and analyzed for trace element concentrations using pEd-XRF run under vacuum conditions. Lead concentrations in urban apples ranged from 0.5 to 1.2 ug/g (dry weight basis). By linking urban fruit lead concentrations with consumption estimates, lead exposure scenarios were modeled. Comparing these results with the EPA regulated benchmark for lead in drinking water shows that consumption of urban fruit does not represent a significant lead exposure pathway that merits immediate concern.

To investigate the potential nutritional benefits of urban fruit, we compared micronutrient levels with those in commercially grown fruits. Calcium concentrations in urban apples and peaches are more than 2.5 times those in their commercial counterparts. Concentrations of Ca, Rb, and Fe were higher in urban fruits for every fruit type tested, and Mn, Zn, Mg, and K concentrations were higher in certain urban fruit types. On average urban fruit contains a wider range of micronutrients than their commercial counterparts. Paired soil and fruit analysis from neighborhoods actively engaging in urban harvesting will provide a means for examining trace element transport pathways within an urban setting.