Survey of Polychlorinated Dibenzo-p-dioxins, Polychlorinated Dibenzofurans, and Non-ortho-polychlorinated Biphenyls in U.S. Meat and Poultry, 2007−2008: Effect of New Toxic Equivalency Factors on Toxic Equivalency Levels, Patterns, and Temporal Trends

Abstract

A statistically based survey of dioxins and dioxin-like compounds in domestic meat and poultry was conducted by the U.S. Department of Agriculture (USDA) from September 2007 to September 2008. Seventeen toxic polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and four non-ortho-polychlorinated biphenyls (no-PCBs) were measured in 510 beef (steer/heifer), market hog, young turkey, and young chicken samples. The results of the survey showed the sum of PCDD/F and no-PCB toxic equivalencies (sum-TEQs) ranging from not detected to 4.5 pg/g of lipid. Mean sum-TEQ levels for beef, turkey, chicken, and pork were 0.66, 0.61, 0.17, and 0.16 pg/g of lipid, respectively. To compare the new survey data with data from previous USDA surveys in the mid-1990s and 2002-2003, TEQs from all data sets were calculated using the most recent 2005 toxic equivalency factors (TEFs). The results of the recalculation on the older survey data was a small increase (4-13%) in mean TEQs for the mid-1990s data, which initially used pre-1994 TEFs, and a small decrease (2-4%) for the 2002-2003 data, which initially used 1998 TEFs. A comparison of the three surveys indicates declining TEQ trends in all slaughter classes over the 10 year period; however, the congener patterns remain relatively constant between 2002 and 2008, indicating similar animal exposures to dioxins and dioxin-like compounds during these time periods. Several samples from the 2008 survey with the highest TEQ values are undergoing follow-up investigations to determine possible sources that may be contributing to these levels.