Total diet market basket food studies (TDS) for POPs at Health Canada

1. Total diet market basket food studies (TDS) for POPs at Health Canada Commission for Environmental Cooperation, Mexico City, Mexico, Oct 26-29, 2010 Dr. John Jake Ryan, consultant Formerly, Health Canada, Ottawa.

2. Presentation Summary • Food as a matrix for dioxin exposure • Measurement of dioxins, furans, and dioxin-like PCBs in biota- what is required • History and organization of TDS • Canadian results of data and trends • (human intake)

3. Health Risk from Chemicals such as Dioxins and HCB • Exposure/Dose Information in North America for levels in common commercial foods (human intake) and body burdens (human uptake) • Adverse effects 1960 to 1980- acute effects In 1970’s possible cancer effects of most concern In 1990’s developmental and reproductive effects most important

4. Persistent Organic PollutantsPOPs • bioaccumulate- solubility low in H2O and high in lipid • persist- resistant to physical, chemical and biological changes • travel long distances- global distillation; related to volatility • adverse effects- impacts organisms negatively in a dose related manner

5. POPs examined PCBs Clx Clx O PCDDs Clx Clx O O PCDFs Clx Clx PBDEs O Brx Brx

6. Human Exposure/Dosing to POPs • Most exposure (>90%) comes from food consumption • Small contribution from air inhalation and even less from drinking water • Significant food sources are those containing animal fats and less so, vegetable fats • In Canada and the United States, these foods are meat (beef, pork, poultry), dairy products (milk, butter, cheese) and fish • Exposure route involves outdoor air to land and water animals then to food

7. Sample analyses at Health Canada • Carbon 13 surrogates • Extraction acetone-hexane • Lipid removal with strong acid or GPC • Chromatography on Florisil • Elution and separation from PCBs in two fractions • Adsorption to carbon

8. Determination by GC/ HRMS • GAS CHROMATOGRAPHY • Column: non polar methyl silicone (DB-5ms) • _ Cool on-column injection: 80°C (1 min), k 35°C/min to 300°C (15 min) • GC oven: 80°C (1 min), k 30°C/min to 200°C, k 5°C/min to 300°C (5 min) run time = 30 min. • _ Interface temp: 270°C • MASS SPECTROMETRY • -8 000 Resolution (10% def.). • EI ~ 40 e.v. • SIM acquisition • of groups tetra- to octa

9. Method Characteristics • - Absolute detection limit for 2,3,7,8-TCDD about 0.05 pg • - Recoveries of carbon-13 surrogates varies between 30-110% • Laboratory blanks positive for OCDD and PCB #77 • in absolute amounts of 5 to 50 pg • QC measures include analysis of reference materials and • participation in performance interlaboratory studies • high specificity and low detectability mean that method • is resource intensive i.e. long and cost high

10. Dioxin Interlaboratory StudyNorway Public Health, 2000-2010 • international performance based program • using own method and standards • analysis of diverse biota (e.g. human milk, beef, pork, chicken, dairy products, eggs, fish) • data for all dioxin-like compounds (WHO TEFs) • other POPs assayed such as PCBs, PBDEs and OCs (HCB, DDTs etc) • statistical evaluation of variation with • establishment of consensus values, Z scores and outliers

11. Total Diet Food Studies • means of estimating human intake based on foods commonly consumed by the general population • first started in 1969 at HC with pesticides and then expanded to POPs and other chemicals • foods sampled at commercial outlets, combined in certain cases, and cooked/processed where applicable • sampling from major cities across country over time along with seasonable selection

12. Canadian Total Diet Study • Provides a direct estimate of the dietary intake of toxic and nutritional chemicals by normal Canadians • Results: • can be compared directly with reference intakes • intake estimates changes • identifies major sources of intake • indicates sources of contaminations (bleaching)

13. DESIGN OF STUDY * Selection of city – usually one city, once a year * Purchase of foods at retail market level not production level * Processing of foods as for consumption -some chemicals and nutrients change on cooking/processing * Chemical Determination * Calculation of dietary intakes using food intake data

14. Collection Cities for Total Diet Studies Whitehorse Vancouver St Johns Calgary Winnipeg Ottawa Toronto Halifax Montreal

15. Estimation of Daily Human Intake of chemical from foodsTwo major components A: Concentration of chemical in food type by chemical determination B: Daily consumption of food type Daily intake = A x B

16. TEQ (D/F) Daily IntakeSampling (n=225) in 1992-1995 Food consumption data from mostly 1972

17. TEQ intake (pg/kg BW/day) by food class1992-1995

18. Body burden of TEQ 60 kg person with 20% lipid = 12 kg fat I: 480 ng total body burden II: 8.0 ng/kg body weight III: 40ng/kg lipid

19. Trends of TEQ (D/F) daily intake in Canadian Total Diet Foods Analyses for years 2000 to 2004 finished and data being processed

20. Canadian TEQ Food Guidelines In 2005 Health Canada adopted the JECFA and FAO tolerable monthly intake value for dioxins and furans of 70 pg TEQ per kg BW equivalent to 2.3 pg TEQ per kg BE per day

21. Reporting Results Scientific Publications Presentations at scientific conferences Health Canada Total Diet Study Report Food Directorate Website http://www.hc-sc.gc.ca/fn-an/surveill/total-diet/index-eng.php

22. Exposure of humans to dioxins from environmental sources still a problem a) PCBs still used and can readily enter the food supply in an uncontrolled manner (Belgium and Irish pork incidents) b) Mined ball clay used in feed/food can contain dioxins c) Dried citrus pulp as animal feed contaminated lime for neutralization c) long range transport followed by food chain accumulation puts selected populations at higher risk to many POPs

23. Mexican Cows’ Milk DataNaccha et al., Dioxin 2010

24. Mexican Issues in food studies • Types of food eaten and comparison to other countries- should be defined • Both Canada and United States have regional and country wide commercial distribution of same foods • -what is the situation in Mexico ? • Due to country-to-country differences in food supply and diet, the WHO recommends that each country conduct its own total diet study. • regional and city differences • specific concerns; eggs from brick kiln areas

25. Summary • Methodology to measure all dioxin-like compounds (29 analytes) has been established and applied to numerous foods; analyses are one of the most challenging • Analyses requires trace analysis experience and high res MS • Human intake of general population in Canada monitored with total diet program which has defined amount and trends for all dioxin-like compound • Comparison made to selected populations and specific incidents

26. ACKNOWLEDGEMENTS Personnel from Health Canada, CFIA and Kemptville College involved in the sample selection, coordination and composite preparation Xu-Liang Cao – Preparation and tabulation of data for website Technical and scientific personnel at Health Canada involved in the determination of all POPs including dioxins and furans in food composites Bob Dabeka for presentation support, background and summary information

27. The End Thank you For your attention Not falling asleep ( I hope!!)