INSIGHTS ALONG THE PATH TO SUSTAINABILITY| November 30, 2005

Ecological and Community Health Impacts of Industrial Food Animal Production: Continuation of project Community Health Risks of Agricultural Antibiotic Use in the Poultry Industry

ELLEN K. SILBERGELD, PhD, Professor, Department of Environmental Health Sciences, JHSPH

SUMMARY

Our project on “Community Health Impacts of Agricultural Antibiotic Use” constitutes the first major community based health study among poultry workers, growers, their families, and community residents in the US.  The goals of this project include: (1) collecting information on health status; (2) collecting and analyzing air samples from poultry houses; (2) collecting and analyzing blood samples for evaluation of biomarkers of exposure and outcome; (4) testing lung function; and (5) establishing a resource of bacterial isolates and DNA for further study, which is now underway. 

The study has been conducted in the Delmarva region of Delaware, Maryland, and Virginia, one of the leading broiler poultry producing areas of the US.  In addition to the continued support of the Center for a Livable Future this project has received support over the past three years from the Winslow Foundation, the Clayton Baker Trust,  the Maryland Cigarette Restitution Fund, and the National Institute for Occupational Safety and Health (CDC)).  Our ability to accomplish research and policy analysis over the past several years has just been recognized by a recent award of $2.8 million from the Pew Charitable Trust.  Our project has been possible only through the invaluable assistance and participation of community leaders, especially Carole Morrison, a poultry grower in Pocomoke City MD whose leadership has been recognized by the Robert W Johnson Foundation, among others.  In addition, we have received generous donations of time and resources by collaborating researchers at Hopkins – particularly Drs EW Spannhake, John Griffin, and Patricia Charache.
 
We have successfully enrolled poultry workers (catchers and live hangers), growers, family members, and community residents in a cross sectional study of exposures and health status, designed to test the hypothesis that the use of antibiotics in poultry production increases the risk of community and worker exposure to antibiotic resistant bacteria.  We collected information on work practices, documenting the lack of occupational protection for workers and growers.  We assessed exposure by measuring bacteria in stool samples, and by using molecular methods to assess antibodies to specific bacteria in serum.  We evaluated health status by questionnaire and by direct testing of respiratory function.
 
The results of this study provide the first epidemiological data (as contrasted with case reports) on the potential risks of exposure to and carriage of drug resistant bacteria.  In addition, there is a high rate of respiratory impairment among community residents and workers in our population, in addition to a high rate of self-reported symptoms of peripheral nervous system dysfunction. 
Our research group has presented result of this research at scientific and other important meetings, including an invited participation in the 2004 regional EPA research conference on CAFOs.  Jay Graham (PhD student) made a major presentation at the 2005 annual meeting of the Association of Schools of Public Health, in Oklahoma, in which he presented the findings from a comprehensive analysis of current policies regarding the management of animal wastes in the U.S.   Lance Price (PhD student) presented a talk on occupational and environmental exposures and health risks associated with poultry production at the National Poultry Justice Alliance Meetings this year. Dr Silbergeld gave an invited talk on arsenic in food animal production at the International Conference on Heavy Metals in the Environment, in Rio de Janeiro in June 2005.  Additional presentations will be made at the annual meeting of the American Public Health Association, the International Conference on Emerging Infectious Disease, ICAC, the next International Symposium on Campylobacter and Related Organisms, among others.

PRESENTER BIOGRAPHY

Ellen Silbergeld trained at Hopkins in environmental engineering sciences (PhD '72) and was a postdoctoral fellow in environmental health sciences. She later held senior scientific positions at Environmental Defense Fund and University of Maryland Medical School. Her research has bridged mechanistic toxicology and environmental health policy. Current research focuses on: lead and genomic imprinting as a mechanism of male mediated developmental toxicity; mercury immunotoxicity and autoimmune disease; and impacts of modern food animal production methods on human health and ecosystems.