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CFSAN/Office of Plant & Dairy Foods
March 2004; Updated November 2004
Dioxin and chemically-related compounds (referred to collectively as dioxin-like compounds or DLCs) are a group of environmental contaminants found throughout the world. Studies have suggested that exposure to high levels of DLCs by industrial workers may lead to reproductive and developmental problems, increased heart diseases, increased diabetes, and increased cancer. Because DLCs tend to accumulate in the fat of food-producing animals, consumption of animal-derived foods (e.g., meat, poultry, eggs, fish, and dairy products) is considered to be the major route of human exposure to low levels of DLCs.
The Food and Drug Administration (FDA) has been concerned about DLCs and has been monitoring food and animal feed with the goal of identifying ways to reduce dietary exposure to these ubiquitous environmental contaminants. In 2000, FDA developed a strategy for DLCs. The purpose of FDA's dioxin strategy, which significantly expanded FDA's Dioxin Monitoring Program, is to develop the science to support appropriate risk management actions. Specific goals for FDA's Dioxin Monitoring Program are to obtain baseline data for DLC levels in food and animal feed ingredients susceptible to DLC contamination and to determine opportunities for DLC reduction by identifying contamination sources that can be eliminated or significantly reduced.
To obtain more general information on dioxin, see Questions and Answers about Dioxin. The Interagency Working Group on Dioxin (IWG) prepared the questions and answers. The Dioxin IWG is composed of U.S. federal agencies that address health, food, and the environment and are working together to ensure a coordinated federal approach to dioxin related issues.
As part of FDA's Dioxin Monitoring Program effort to obtain baseline data for DLCs, FDA analyzes food and feed for DLCs from both targeted sampling and food collected under its Total Diet Study (TDS). The TDS is FDA's ongoing market basket survey of approximately 280 core foods in the U.S. food supply to determine levels of various pesticides residues, contaminants, and nutrients in foods and to estimate intakes of these substances in representative diets of specific age-sex groups in the U.S. Four market baskets are generally collected each year, once in each of four geographic regions of the U.S. (i.e., West, North Central, South, and Northeast). For each market basket, food samples are collected from grocery stores and fast food restaurants in three cities within the region, prepared table-ready (i.e., as they would be consumed), and composited for analysis (See General notes on food preparation prior to analysis). Therefore, each data point for a pesticide residue, contaminant or a nutrient represents a composite of three samples of a table-ready (i.e., cooked, if required by TDS recipes) food type. For more information see the Total Diet Study Overview.
FDA's Dioxin Monitoring Program analyzed TDS samples from one market basket each year in 2000, 2001 and 2002, to determine levels of polychlorinated dibenzo-p-dioxin (PCDD) and polychlorinated dibenzofuran (PCDF) congeners. The market basket analyzed in 2000 contained TDS samples from Tucson, Arizona, San Diego, California, and Brownsville, Texas. The market basket analyzed in 2001 contained TDS samples from Colorado Springs, Colorado, Oakland, California and Spokane, Washington. The market basket analyzed in 2002 contained TDS samples from Ventura County, California, San Jose, California and Yakima, Washington. In 2000, TDS samples analyzed for PCDD/PCDF congeners represent only FDA regulated products. In 2001 and 2002, TDS samples analyzed for PCDD/PCDF congeners represent a broader range of TDS samples.
TDS samples were analyzed by gas chromatography/high resolution mass spectroscopy (HRMS), unless otherwise noted, for 17 PCDD/PCDF congeners listed in Table 1. Data for PCDD/PCDF congener concentrations in TDS samples are presented as Toxicity Equivalents or TEQs which are used to estimate the relative toxicity of congeners. This equivalency method is based on summing the TEQs of 17 PCDD/PCDF congeners in each sample. The TEQ is calculated by multiplying the concentration of each PCDD and PCDF congener by the corresponding 1998 World Health Organization Toxic Equivalency Factor or TEF listed in Table 1. The TEF of the most potent PCDD/PCDF congener called 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is 1. Three TEQ values were generated for each PCDD and PCDF congener and for each TDS sample, reflecting assignment of zero, half the limit of detection (LOD), or LOD values to congener non-detects. All results are expressed on a whole weight basis.
| Congener | TEF(1) | ||
|---|---|---|---|
| Polychlorinated Dibenzodioxins | |||
| 2,3,7,8-TCDD | 1 | ||
| 1,2,3,7,8-PeCDD | 1 | ||
| 1,2,3,4,7,8-HxCDD | 0.1 | ||
| 1,2,3,6,7,8-HxCDD | 0.1 | ||
| 1,2,3,6,7,9-HxCDD | 0.1 | ||
| 1,2,3,4,6,7,8-HpCDD | 0.01 | ||
| OCDD | 0.0001 | ||
| Polychlorinated Dibenzofurans | |||
| 2,3,7,8-TCDF | 0.1 | ||
| 1,2,3,7,8-PeCDF | 0.05 | ||
| 2,3,4,7,8-PeCDF | 0.5 | ||
| 1,2,3,4,7,8-HxCDF | 0.1 | ||
| 1,2,3,6,7,8-HxCDF | 0.1 | ||
| 1,2,3,7,8,9-HxCDF | 0.1 | ||
| 2,3,4,6,7,8-HxCDF | 0.1 | ||
| 1,2,3,4,6,7,8-HpCDF | 0.01 | ||
| 1,2,3,4,7,8,9-HpCDF | 0.01 | ||
| OCDF | 0.0001 | ||
| 1 van den Berg M, Birnbaum L, Bosveld AT, Brunstrom B, Cook P, Feeley M, Giesy JP, Hanberg A, Hasegawa R, Kennedy SW, Kubiak T, Larsen JC, van Leeuwen FX, Liem AK, Nolt C, Peterson RE, Poellinger L, Safe S, Schrenk D, Tillitt D, Tyskind M, Younes M, Waern F, Zacharewski T. 1998. Toxic equivalency factors (TEF) for PCBs, PCDDs, PCDFs for humans and wildlife. Environ Health Perspect 106: 775-792. | |||
Each results file is a self-extracting compressed (zipped), tab-delimited text file that can be downloaded, decompressed (double-click the file or use a program like Stuffit Expander), and imported by database or spreadsheet software. For best viewing and data manipulation, the text files should be saved and then opened from a database or spreadsheet program such as Microsoft Excel, Corel QuattroPro and Lotus 1-2-3.
Summary of dioxin (PCDD/PCDF) concentration results:
FY 2000 Summary File
FY 2001 Summary File
FY 2002 Summary File
Congener specific dioxin (PCDD/PCDF) concentration results:
FY 2000 Congener File
FY 2001 Congener File
FY 2002 Congener File
Help with compressed ZIP and EXE files
Added fat:
Unless noted in the food description, fat was not added to foods after cooking
(e.g., cooked vegetables, breads and rolls, pancakes, cooked cereals/grains)
Eggs:
Fried and scrambled eggs: were cooked in vegetable oil
Meats:
Cooked meats: cooking fat/pan drippings were drained and excess fat trimmed
Pan-cooked meats: were cooked in vegetable oil.
Brown gravy: was prepared with meat drippings
Poultry:
Fried chicken: included light and dark meat, skin was included
Roasted: included light meat only, skin was included
Turkey breast: light meat only, skin was removed
Fish:
Pan-cooked fish: was cooked in vegetable oil
Canned tuna: oil was drained
Vegetables:
Mashed potatoes: were prepared from package using whole milk and margarine
Cream soups:
Tomato soup: was prepared with water
Clam chowder: was prepared with whole milk
Desserts:
Chocolate pudding: was prepared with whole milk
