Lead in New York City community garden chicken eggs: influential factors and health implications
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Raising chickens for eggs in urban areas is becoming increasingly common. Urban chickens may be exposed to lead, a common urban soil contaminant. We measured lead concentrations in chicken eggs from New York City (NYC) community gardens and collected information on factors that might affect those concentrations. Lead was detected between 10 and 167 μg/kg in 48 % of NYC eggs. Measures of lead in eggs from a henhouse were significantly associated (p < 0.005) with lead concentrations in soil. The association between soil and egg lead has been evaluated only once before, by a study of a rural region in Belgium. In our study, the apparent lead soil-to-egg transfer efficiency was considerably lower than that found in Belgium, suggesting that there may be important geographic differences in this transfer. We developed models that suggested that, for sites like ours, lead concentrations in >50 % of eggs from a henhouse would exceed store-bought egg concentrations (<7–13 μg/kg; 3 % above detection limit) at soil lead concentrations >120 mg/kg and that the concentration in one of six eggs from a henhouse would exceed a 100 μg/kg guidance value at soil lead concentrations >410 mg/kg. Our models also suggested that the availability of dietary calcium supplements was another influential factor that reduced egg lead concentrations. Estimates of health risk from consuming eggs with the lead concentrations we measured generally were not significant. However, soil lead concentrations in this study were <600 mg/kg, and considerably higher concentrations are not uncommon. Efforts to reduce lead transfer to chicken eggs and associated exposure are recommended for urban chicken keepers.
KeywordsChicken eggs Lead (Pb) exposure Community gardens Urban agriculture Exposure assessment
The authors would like to acknowledge the assistance of colleagues from the Healthy Soils, Healthy Communities project partner organizations, particularly Stephen Shost and Jan Storm of the New York State Department of Health and Edie Stone of New York City’s GreenThumb program. We are also grateful to Just Food for their contributions to this project, including the time and energy of Gregory Anderson and “chicken interns” Meredith Wells, Marlie Wilson, L. Reed, and Rafael Aponte. Most importantly, we thank the many community gardeners and chicken keepers who have participated in this project. Funding for this research was provided by the National Institutes of Health/National Institute of Environmental Health Sciences, Award Number R21ES017921 from the National Institute of Environmental Health Sciences (NIEHS). The content is solely the responsibility of the authors and does not necessarily represent the official views of NIEHS or the National Institutes of Health.
- ATSDR. (2007). Toxicological profile for lead. Atlanta, GA: Agency for Toxic Substances and Disease Registry, Public Health Service, US Department of Health and Human Services.Google Scholar
- Bakalli, R. I., Pesti, G. M., & Ragland, W. L. (1995). The magnitude of lead toxicity in broiler chickens. Veterinary and Human Toxicology, 37(1), 15–19.Google Scholar
- Bartling, H. (2010). Chicken ordinance survey. Chicago, IL: DePaul University. Retrieved from http://www.cityofbatavia.net/content/articlefiles/7186-Suburban%20Chickens.pdf.
- Beam, A., Garber, L., Sakugawa, J., & Kopral, C. (2013). Salmonella awareness and related management practices in U.S. urban backyard chicken flocks. Preventive Veterinary Medicine. doi: 10.1016/j.prevetmed.2012.12.004.
- CalEPA. (2007). Development of Health Criteria for School Site Risk Assessment Pursuant to Health and Safety Code Section 901(g): Child-Specific Benchmark Change in Blood Lead Concentration for School Site Risk Assessment. Integrated Risk Assessment Branch Office of Environmental Health Hazard Assessment California Environmental Protection Agency. Retrieved from http://www.oehha.org/public_info/public/kids/pdf/PbHGV041307.pdf.
- California DHS. (2004). Backyard chicken eggs in California: Reducing risks questions and answers. Environmental Health Investigations Branch, California Department of Health Services. Retrieved from http://www.ehib.org/papers/caeggs8by11c.pdf.
- CDC. (2012). CDC Response to Advisory Committee on Childhood Lead Poisoning Prevention Recommendations in “Low Level Lead Exposure Harms Children: A Renewed Call of Primary Prevention.” US Department of Health and Human Services, CDC.Google Scholar
- EC. (2006). Commission regulation (EC) No 1881/2006 of 19 December 2006 setting maximum levels for certain contaminants in foodstuffs. Official Journal of the European Union, L, 364, 06–24.Google Scholar
- Food Standards Agency. (2004). 2000 Total diet study of 12 elements—aluminium, arsenic, cadmium, chromium, copper, lead, manganese, mercury, nickel, selenium, tin and zinc (No. FSIS 48/04). UK Food Standards Agency.Google Scholar
- Gittleman, M., Librizzi, L., & Stone, E. (2010). Community garden survey New York City results 2009/2010. GrowNYC. Retrieved from http://www.greenthumbnyc.org/pdf/GrowNYC_community_garden_report.pdf.
- Mahaffey, K. R., Gartside, P. S., & Glueck, C. J. (1986). Blood lead levels and dietary calcium intake in 1- to 11-year-old children: The second national health and nutrition examination survey, 1976 to 1980. Pediatrics, 78(2), 257–262.Google Scholar
- NYSDEC. (2006). New York state brownfield cleanup program development of soil cleanup objectives technical support document. Appendix D. New York State Department of Environmental Conservation. Retrieved from http://www.dec.ny.gov/docs/remediation_hudson_pdf/appendixde.pdf.
- Smith, E., Kempson, I. M., Juhasz, A. L., Weber, J., Rofe, A., Gancarz, D., et al. (2011). In vivo-in vitro and XANES spectroscopy assessments of lead bioavailability in contaminated periurban soils. Environmental Science and Technology, 45(14), 6145–6152. doi: 10.1021/es200653k.CrossRefGoogle Scholar
- US FDA. (2006). Supporting document for recommended maximum level for lead in candy likely to be consumed frequently by small children [Docket No. 2005D-0481] (WebContent). US Food and Drug Administration. Retrieved from http://www.fda.gov/food/foodsafety/foodcontaminantsadulteration/metals/lead/ucm172050.htm.
- US FDA. (2007). Total diet study statistics on element results revision 4.1, market baskets 1991–3 through 2005-4. College Park, MD: US Food and Drug Administration. Retrieved from http://www.fda.gov/downloads/Food/FoodSafety/FoodContaminantsAdulteration/TotalDietStudy/UCM243059.pdf.
- US FDA. (2010) Total diet study statistics on element results market baskets 2006-1 through 2008-4. College Park, MD: US Food and Drug Administration, Center for Food Safety and Applied Nutrition. Retrieved from http://www.fda.gov/downloads/Food/FoodSafety/FoodContaminantsAdulteration/TotalDietStudy/UCM184301.pdf.
- USDA & HHS. (2010). Dietary guidelines for Americans 2010. Washington, DC: US Government Printing Office: US Department of Agriculture and US Department of Health and Human Services.Google Scholar
- US EPA. (1998). Final report sources of lead in soil: A literature review EPA 747-R-98-001a. Washington, DC: National Center for Environmental Assessment, US Environmental Protection Agency.Google Scholar
- US EPA. (2005). Human health risk assessment protocol for hazardous waste combustion facilities EPA530-R-05-006. Washington, DC: Office of Solid Waste and Emergency Response, US Environmental Protection Agency.Google Scholar
- US EPA. (2008). Child-specific exposure factors handbook EPA/600/R-06/096F. Washingon, DC: National Center for Environmental Assessment, US Environmental Protection Agency.Google Scholar
- Waegeneers, N., De Steur, H., De Temmerman, L., Van Steenwinkel, S., Gellynck, X., & Viaene, J. (2009a). Transfer of soil contaminants to home-produced eggs and preventive measures to reduce contamination. Science of the Total Environment, 407(15), 4438–4446. doi: 10.1016/j.scitotenv.2008.12.041.CrossRefGoogle Scholar