| Assessing Potential Risk of Heavy Metal Exposure from Consumption of Home-Produced Vegetables by Urban Populations Rupert L. Hough,1 Neil Breward,2 Scott D. Young,1 Neil M. J. Crout,1 Andrew M. Tye,1 Ann M. Moir,3 and Iain Thornton3 1School of Bioscience, University of Nottingham, Nottingham, United Kingdom; 2British Geological Survey, Keyworth, Nottingham, United Kingdom; 3Environmental Geochemistry Research Group, Department of Environmental Science and Technology, Royal School of Mines, Prince Consort Road, London, United Kingdom Abstract
We performed a risk assessment of metal exposure to population subgroups living on, and growing food on, urban sites. We modeled uptake of cadmium, copper, nickel, lead, and zinc for a selection of commonly grown allotment and garden vegetables. Generalized linear cross-validation showed that final predictions of Cd, Cu, Ni, and Zn content of food crops were satisfactory, whereas the Pb uptake models were less robust. We used predicted concentrations of metals in the vegetables to assess the risk of exposure to human populations from homegrown food sources. Risks from other exposure pathways (consumption of commercially produced foodstuffs, dust inhalation, and soil ingestion) were also estimated. These models were applied to a geochemical database of an urban conurbation in the West Midlands, United Kingdom. Risk, defined as a "hazard index," was mapped for three population subgroups: average person, highly exposed person, and the highly exposed infant (assumed to be a 2-year-old child) . The results showed that food grown on 92% of the urban area presented minimal risk to the average person subgroup. However, more vulnerable population subgroups (highly exposed person and the highly exposed infant) were subject to hazard index values greater than unity. This study highlights the importance of site-specific risk assessment and the "suitable for use" approach to urban redevelopment. Key words: exposure, hazard index, mapping, metals, risk, urban, vegetables. Environ Health Perspect 112:215-221 (2004) . doi:10.1289/ehp.5589 available via http://dx.doi.org/ [Online 31 October 2003]
Address correspondence to R.L. Hough, Public and Environmental Health Research Unit, London School of Hygiene and Tropical Medicine, 1 Keppel Street, London, WC1E 7HT, U.K. Telephone: 44(0) 20 7927 2442. Fax: 44(0) 20 7580 4524. E-mail: Rupert.Hough@LSHTM.ac.uk We thank the Natural Environment Research Council's Urban Regeneration and the Environment program, and the Biotechnology and Biological Sciences Research Council of the United Kingdom for funding this work. The authors declare they have no competing financial interests. Received 7 March 2002 ; accepted 30 October 2003. Tables 3-7 were corrected on 11 March 2004. These corrections were printed in the April issue of EHP.
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