Dioxins, furans and non-ortho-PCBs in Canadian total diet foods 1992–1999 and 1985–1988

Abstract

In the period from 1985 to 1999, about 600 samples of total diet foods from Canadian cites were analysed for dioxins, furans and non-ortho-PCBs. Toxic equivalent (TEQ) concentrations on a lipid basis were found to be the highest in dairy and beef products followed by poultry and pork. These levels decreased over the 15-year period of sampling, particularly those for fluid milk, less so for poultry and pork and little or no change for beef. Calculation of the human daily intake for the years 1985–1988 showed values a little less than 1 pg of TEQ₂₀₀₅ polychlorinated dibenzo-p-dioxin/polychlorinated dibenzofuran per kg body weight, falling progressively to less than 0.5 pg of TEQ in 1999. These estimates are lower than the 2.3 pg of TEQ currently recommended by the WHO. The main categories of foods contributing to the TEQ were animal meats and dairy products, with lesser amounts from fish and other foods.

Keywords:

• chlorinated dibenzo-p-dioxins
• chlorinated dibenzofurans
• dioxins
• furans
• PCDDs
• PCDFs
• non-ortho-PCBs
• TEQ
• POPs
• total diet
• Canadian foods
• chemical contaminants
• daily intake

Acknowledgements

The authors acknowledge the initiative, stimulation and efforts of Rudolf Krska, University of Natural Resources and Life Sciences, Tulln, Vienna, Austria, in facilitating the combination and publication of these chemical findings during his sabbatical stay in Canada in 2009–2010. The first author is also grateful to Thea Rawn, Health Canada, for her efforts in obtaining financial support for the preparation of this manuscript along with related work.

In the procuring of food samples and preparation of sample composites, the authors are grateful to the following groups/people from Health Canada: Field Operations for purchasing food samples in 1992–1996, Russ Graham (retired) for sampling in 1985–1996 and Frank Lancaster (retired) for sampling in 1998–1999. The Department of Indian Affairs & Indian Development collected food samples from Whitehorse in 1998. The Food Service and Nutrition group at Kemptville College, University of Guelph, prepared most of the food composites for this work.

For the numerous and detailed generation of analytical numbers on these contaminants in foods, especially the need for low detection limits and high analyte specificity, we thank the following individuals from Health Canada: (1) for sample preparation and separation, Raymonde Lizotte, Luz G. Panopio, Pat Mills, Brian Shields and Nicole Beaudoin; and (2) for mass spectral determination, Benjamin P.-Y. Lau, Dave A. Lewis, Benoit Patry and Wing F- Sun. The regional laboratories of Health Canada are also acknowledged for their efforts in the generation of these data including (1) for the Western Regional Laboratory, Brian Mori, Kenneth Breakall, Victor Verigin, Carl Alleyne and Helen Nicolidakis; and (2) for the Ontario Regional Laboratory, Bob Neil, Pat Calway, Peter Pantazopoulos and Michael Dowd.

Beata Kolakowski of the Canadian Food Inspection Agency, Ottawa, is thanked for obtaining permission to use some of their unpublished analytical monitoring food data on dioxins and furans along with information on web-based numbers. Lastly, Henry B.S. Conacher is acknowledged for his general support during the entire period of the total diet food program by fostering this work as a means of estimating the exposure and risk of chemicals in foods.