Total diet market basket food studies tds for pops at health canada
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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. Presentation Summary. Food as a matrix for dioxin exposure

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Total diet market basket food studies tds for pops at health canada

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.


Presentation summary

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)


Health risk from chemicals such as dioxins and hcb

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


Persistent organic pollutants pops

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


Pops examined

POPs examined

PCBs

Clx

Clx

O

PCDDs

Clx

Clx

O

O

PCDFs

Clx

Clx

PBDEs

O

Brx

Brx


Human exposure dosing to pops

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


Sample analyses at health canada

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


Determination by gc hrms

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


Method characteristics

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


Dioxin interlaboratory study norway public health 2000 2010

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


Total diet food studies

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


Total diet market basket food studies tds for pops at health canada

  • 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)


Total diet market basket food studies tds for pops at health canada

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


Total diet market basket food studies tds for pops at health canada

Collection Cities for Total Diet Studies

Whitehorse

Vancouver

St Johns

Calgary

Winnipeg

Ottawa

Toronto

Halifax

Montreal


Estimation of daily human intake of chemical from foods two major components

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


Teq d f daily intake sampling n 225 in 1992 1995

TEQ (D/F) Daily IntakeSampling (n=225) in 1992-1995

Food consumption data from mostly 1972


Teq intake pg kg bw day by food class 1992 1995

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


Body burden of teq

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


Trends of teq d f daily intake in canadian total diet foods

Trends of TEQ (D/F) daily intake in Canadian Total Diet Foods

Analyses for years 2000 to 2004 finished and data being processed


Canadian teq food guidelines

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


Total diet market basket food studies tds for pops at health canada

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


Exposure of humans to dioxins from environmental sources still a problem

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


Mexican cows milk data naccha et al dioxin 2010

Mexican Cows’ Milk DataNaccha et al., Dioxin 2010


Mexican issues in food studies

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


Summary

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


Total diet market basket food studies tds for pops at health canada

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


The end

The End

Thank you

For your attention

Not falling asleep ( I hope!!)


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