Xtrafood - University of Reading · measured mean predicted background predicted Menen measured Menen group 3: sum PCDD/PCDF 0 2000 4000 6000 8000 10000 12000 milk fat pg TEQ / kg

1November 7, 2007 confidential – © 2006, VITO NV – all rights reserved

Chain model for the impact analysisof contaminants in primary food

products

Xtrafood

Katleen De Brouwere, Christa Cornelis and Mirja Van HolderbekeIntegral Environmental Studies, VITO


Content

1. The Xtrafood model: general concept– transfer and exposure

– database structure and programming

2. Application of the Xtrafood model– development of guideline values for

atmospheric deposition of dioxins and PCBs in Flanders


integration transfer and exposure in 1 model

transfer module

environment (soil, water, air, deposition)

crops

cattle

exposure module

food package

dietary exposurelimits

1. Xtrafood: general concept

TDI


Transfer

Net atmospheric

deposition

Crop productionAnimal productionFarm

P-fertilizersManure

Leaching

Feed

Soil

Water

Fodder

Potatoes

Milk

Muscle

Kidney and liver

Vegetables

Fruit

Cereals


transfer module plant:

1. air-to-plant transfer: kinetic physically based model including (McLachlan et al., 1999)• dry gaseous deposition• dry and wet particle deposition

2. dynamic root uptake model (Trapp, 2002)

crop propertiesplant height,interception, leaf surface area,

…air concentrationsoil concentrationdeposition datachemical & fysical constants

Koa, Kow, Henry Ct,…

model input

Cplant :concentrationin cropdue to atmosphere + soil

model output

model calculation


transfer module cattle

intake (fodder, grass, soil,

water, concentrate)

digestion

blood

milk

muscle/fat

steady-state model

animal properties : fodder and water consumption, milk production, soil ingestion.

fodder crops (composition, ~ transfer plant)soil (and water) concentrationtransferfactors BTF, BCF, CORfysico-chemical contstants

model input

Cmilk, Cmuscle (~ fat content)

ClliverCkidneyCeggs

model output

faeces


Exposure

milkmuscleliver and kidney

cerealspotatoesvegetables

fruit

transfer

primaryanimalproducts

primarycrop

products

exposure via food

secondary and composed food

human diet

foodpreparation

not-farmproducts

origin of primaryproducts

detailed food consumption data of 3 studies (B) (UGhent, Department Public Health)


Xtrafood model: databasestructure and programmering

• SQL-environment:

formulas in SQL-language combined withdatabases in MS-Access

• Databases on– agriculture and environment

– exposure and link with transfer


databases agriculture and environment– contaminants (63)

fysico-chemical properties, biotransferfactors (muscle, milk, eggs, …), CAS-number,…

– cropsNIS-code, yield, crop properties, Cd-BCF-factors, growth period,…

– cattleNIS-code, weight, milk production, fodder- and water consumption,pasture period,…

– soilssoil type, land use, pH, OC, bulk density,…

– environmental parametersCAS-number, location, deposition, air,water and soil concentration,…

– fertilitizationtype (manure, mineral fertilizer, sludge,…), concentration, CAS-number, dose


databases exposure and link with transfer

– population categoryage, gender, weight

– food classes code + description main classes and subclasses

– daily food intake food (code), population category, average, median, P5, P25, P75 and P95 consumption

– link food – primary (farm) product– food preparation

contaminant, food (code), process (washing, peeling, boiling, frying), reduction factor

– product origin– not-farm related (primary) products


Application of the Xtrafood model:

development of critical values for atmospheric deposition of dioxins and

PCBs in Flanders

(study performed on behalf of the VMM, Flemish Waste Agency)


environment (soil, water, air, deposition)

crops

cattle

food package

dietary exposureTDI

“Determine critical deposition values for dioxins and PCBs for Flanders in order to protect human health”


Scientific point of view:

each individual dioxin and PCB

(congener) has its own specific

fysico -chemical properties and bio-

accumulation behaviour

accross environment – food chain:

component-by component modelling

policy-oriented point of view:

simple, easy to use guidelines!

If possible for dioxins and/or

PCBs as one group

compromis:

Guidelines for groups of congeners

DL-PCBs PCDD/F NDL-PCBs


� Based on congener distribution in deposition and

exposure and based on physico-chemical and

biotransfer properties:1. NDL – PCBs: PCB-28/52/101

2. NDL – PCBs: PCB138/153/180

3. PCDD/F’s 2,3,7,8-TCDD

4. DL-PCB’s PCB-126

5. PCDD/F’s + DL-PCB’s 2,3,7,8-TCDD

� transfer of all congeners in one group simplified by

transfer of marker of the group

Grouping of dioxins and PCBs


validation Xtrafood model for dioxins/PCBs

0

5

10

15

20

25

30

35

40

Aardappelen Wortelen Voederbieten

pg TEQ/kg v.g.

model - Menen model - achtergrond

gemeten - Menen gemeten - gemiddeld

measurements: not peeled crops

model: washed, peeled crop

group 3:sum PCDD/PCDF

potatoes carrots fodder beet

– root crops


-above ground crops

01020

3040506070

8090100

Alle groenten Alle verse

groenten in

serres

Courgettes Pompoen Bloemkolen

pg TEQ /kg v.g.

model - Menen model - achtergrond gemeten gemeten - Menen


vegetables vegetables

grown in

greenhouse

courgette pumpkin cauliflower


-cattle

0

2000

4000

6000

8000

10000

12000

14000

16000

18000

20000

egg fat

pg TEQ / kg fat

measured mean predicted background

predicted Menen measured Menen


0

2000

4000

6000

8000

10000

12000

milk fat

pg TEQ / kg fat

measured mean predicted background

predicted Menen measured Menen


group 5:sum PCDD

/PCDF + PL-PCBs

– average total dietary exposure (Flanders)‘classical’ modelling based on actual average deposition

levels and soil concentration in Flanders;

data for Flemish women 21- 30 years

sum Xtrafood

model = 94 pg

TEQ/day

review : 155 pg

TEQ/day0

5

10

15

20

25

30

35

40

45

Bre

ad &

bre

adpr

oduc

ts

Egg

s

Fruit

Pou

ltry

Gra

in p

rodu

cts

Veg

etab

les

Che

ese

Milk

and

milk

pro

ducts

Org

ans

Red

mea

tSau

ces

Whe

at flou

r

Fat

Fish

and

she

llfish

pg TEQ/day

prediction review


Xtrafood ‘inverse’ modelling to derive deposition thresholds

• Iterative process : calculate critical deposition, i.e. at which the total exposure equals the TDI (e.g. TDI dioxins + DL-PCBs : 2 pg TEQ/day/kg

9,827,998,21

0

0,5

1

1,5

2

2,5

0,00 2,00 4,00 6,00 8,00 10,00 12,00

depositie (pg TEQ /m2.dag)

dosis (pg P

CDD/F

's+DL-P

CB's

TEQ/kg.d

ag)

mannen levenslang vrouwen levenslang vrouwen vruchtbaar

Dose (pg TEQ/kg/day) =

A + B x deposition (pg TEQ/m³/day)

A = 1.18

B = 0.99

TDI


NOAEL/10:

10.6 ng/kg.day

NOAEL/10:

10.6 ng/kg.day

TDI:

2pg TEQ/kg.day

TDI:

2pg TEQ/kg.day

TDI:

2pg TEQ/kg.day

threshold

27 ng/m²/day0.156.4PCB138/153/180

(as PCB153)

163 ng/m²/day0.051.6PCB28/52/101 (as PCB28)

13 pg TEQ/m².day0.09980.67PCDD/F

15 pg TEQ/m².day0.09480.50DL-PCBs (as PCB126)

8.2 pg TEQ/m².day0.09981.18PCDD/F/DL-PCBs

proposed critical

deposition value

(pg TEQ/m².day)

BAgroup


conclusion/outlook

• Xtrafood model: tool available to model transfer of pollutants through the whole food chain

• Tool allows to derive critical deposition thresholds for dioxins and PCBs

• Other options: to assess the impact of policy measures (e.g. limits in animals feed, deposition…) on total dietary intake

Documents

Xtrafood - University of Reading · measured mean predicted background predicted Menen measured Menen group 3: sum PCDD/PCDF 0 2000 4000 6000 8000 10000 12000 milk fat pg TEQ / kg