Xtrafood - University of Reading · measured mean predicted background predicted Menen measured...
Transcript of Xtrafood - University of Reading · measured mean predicted background predicted Menen measured...
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
2November 7, 2007 confidential – © 2006, VITO NV – all rights reserved
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
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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
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Transfer
Net atmospheric
deposition
Crop productionAnimal productionFarm
P-fertilizersManure
Leaching
Feed
Soil
Water
Fodder
Potatoes
Milk
Muscle
Kidney and liver
Vegetables
Fruit
Cereals
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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
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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
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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)
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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
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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
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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
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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)
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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”
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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
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� 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
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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
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-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
group 3:sum PCDD/PCDF
vegetables vegetables
grown in
greenhouse
courgette pumpkin cauliflower
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-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
group 3:sum PCDD/PCDF
0
2000
4000
6000
8000
10000
12000
milk fat
pg TEQ / kg fat
measured mean predicted background
predicted Menen measured Menen
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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
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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
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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
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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