Survey of polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans and non-ortho-polychlorinated biphenyls in U.S. meat and poultry from 2018-2019: Toxic equivalency levels, temporal trends, and implications

Authors: Lupton, Sara; OCHOA, CRISTIAN - Food Safety Inspection Service (FSIS); DOMESLE, ALEXANDER - Food Safety Inspection Service (FSIS); DUVERNA, RANDOLPH - Food Safety Inspection Service (FSIS)

Submitted to: Food Additives & Contaminants
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/16/2021
Publication Date: 2/3/2022
Citation: Lupton, S.J., Ochoa, C., Domesle, A., Duverna, R. 2022. Survey of polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans and non-ortho-polychlorinated biphenyls in U.S. meat and poultry from 2018-2019: Toxic equivalency levels, temporal trends, and implications. Food Additives & Contaminants. 39:560-571. https://doi.org/10.1080/19440049.2021.2022769.
DOI: https://doi.org/10.1080/19440049.2021.2022769

Interpretive Summary: Polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs) and polychlorinated biphenyls (PCBs) are environmental contaminants classified as persistent organic pollutants (POPs) by the Stockholm Convention. PCDD/Fs are waste products from industrial applications such as incineration processes. PCBs, however, were man-made and introduced into different industrial and consumer products. PCDD/Fs and PCBs have the ability to accumulate in fat. As a result, consumers are exposed to these compounds through meat products regulated by the United States Department of Agriculture-Food Safety and Inspection Service. The FSIS and Agricultural Research Service have conducted surveys every 5 years of fat samples from cattle, swine, chickens, and turkeys directly from animal processing facilities over the last two decades. These surveys were completed to determine background levels of PCDD/Fs and PCBs and temporal trends of mean and median values observed in the surveys. Overall, levels of these contaminants have decreased over the last 20 years in domestic meat, however, in the recent survey beef and hog levels have plateaued. Results from these surveys are also used to investigate unusually high levels found to determine possible contamination sources (i.e. feed, treated wood, incineration ash). Understanding current background levels of dioxins, furans, and PCBs in meats produced in the United States provides meaningful data for risk assessors who estimate consumer exposures to these contaminant classes.

Technical Abstract: The U.S. Department of Agriculture (USDA) conducted a statistically-based survey of the domestic meat supply (beef, pork, chicken, turkey, dairy cow, and catfish) to determine the current residue levels of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and non-ortho-polychlorinated biphenyls (no-PCBs). The survey is conducted every 5 years. Fat samples for each slaughter class and catfish fillets were collected from U.S. federally inspected slaughter facilities, processed, and analyzed for 17 PCDD/Fs and 3 no-PCBs. Toxic equivalency concentrations were calculated using 2005 toxic equivalency factors and summed (sum-TEQ) for all slaughter classes. The sum-TEQs ranged from non-detect (nd) to 16.5 pg TEQ/g lipid. The median sum-TEQs, when nd = ½ LOD, for beef, pork, chicken, turkey, dairy cow, and catfish were 0.48, 0.08, 0.07, 0.21, 0.38, and 0.62 pg TEQ/g lipid (wet weight for catfish), respectively. A comparison of the current and previous surveys typically depicts a significant declining trend depending on the slaughter class (such as chicken and turkey), however beef and market hog median values slightly increased and decreased, respectively, but neither were significant compared to the previous survey. The congener patterns for some high concentration beef and market hog samples suggested that pentachlorophenol treated wood continues to be a likely on-farm dioxin exposure source.