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Risk Assessment of Lead, PCBs and PBDEs in Poultry Eggs from Commercial Free-Range and Pastured Poultry Farms in California


The overwhelming majority of food safety research associated with commercial free-range and pastured poultry has focused on microbial food safety risks. While human illness from most foodborne pathogens is limited to transient gastrointestinal symptoms, there are numerous environmental contaminants in California that pose a substantial food safety risk and have the potential to cause long term adverse health effects. Specifically, lead (Pb), polychlorinated biphenyls (PCBs), and polybrominated diphenyl ethers (PBDEs), are of particular concern due to their high prevalence in the environment and their ability to cause potentially irreversible endocrine and neurologic impairment in both adults and children. Recent studies show that Pb is detectable in the tissues and eggs of CA's backyard chickens at levels that can pose a public health risk. For example, the consumption of one average size 60 gram egg can approach the designated maximum daily allowance of 6µg of Pb. The adverse health effects of Pb have been well documented in humans. Despite the ban of PCBs in the 1970s and certain classes of PBDEs in 2004, these compounds are ubiquitous in the environment. The highest levels of persistent organic pollutants (POP), including PCBs and PBDEs, have been found in the Western US. Elevated concentrations of PBDEs and PCBs have been observed in Europe for more than a decade in eggs from free range chickens. A recent study from Tanzania confirmed the risk for exposure to PCBs and PBDEs egg consumption and highlighted the importance of local environmental contamination assessment and prevention strategies. The recent detection PCBs and PBDEs in commercial milk produced in CA highlights the importance to assess PCBs and PBDEs in eggs from poultry in CA to identify potential non-point sources and generate essential data for the development of mitigation strategies. With the increased exposure to the environment associated with free-range and pastured poultry production, the potential for increased exposure to these chemicals exists. However, no studies to date have assessed the chemical contamination of eggs from commercial free range and pastured poultry to gain a better understanding of exposure risks to consumers.Objective 1. Identify environments where free-range and pastured poultry exist in addition to environmental persistence of high Pb, PCBs and PBDEs. Develop and implement recruitment strategy for 10 commercial free-range and pastured poultry farms in areas of high and low risk exposure to environmental contaminants.Objective 2. Qualitative and quantitative measure of Pb, PCBs, and PBDEs in chicken eggs. Develop risk maps hosted on the UCCE poultry website to facilitate outreach to farmers, retailers and consumers.Objective 3. Extend knowledge to commercial free-range and pastured poultry producers in CA via the UCCE poultry website and via a recently awarded 3-year USDA grant that requires 7 in person training courses per year for 3 years. In addition, results will be shared with the Office of Environmental Health Hazard Assessment (OEHHA) and the CA Department of Food and Agriculture (CDFA) to foster science-based regulations if necessary and to help ensure rational food safety practices and promote safe table eggs

Puschner, Birgit
University of California - Davis
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