cd , pb and zn oral bioaccessibility in urban soils in … bioacc rousselh.pdf · cd , pb and zn...
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CdCd, , PbPb and Zn oral and Zn oral
bioaccessibility in urban soils in bioaccessibility in urban soils in
the vicinity of two lead and zinc the vicinity of two lead and zinc
smelterssmelters
RousselRoussel H.H., , WaterlotWaterlot C., C., PruvotPruvot C., Douay F.C., Douay F.
Laboratory of Soils and Environment, Institut Supérieur d’Agriculture, 48 boulevard Vauban, Lille - France
ContextContext
•• HistoricHistoric
contaminationcontamination
� Metaleurop Nord (Noyelles-Godault) = Lead smelter
� Umicore (Auby) = Zinc smelter
ContextContext•• High contamination of urban soils used for High contamination of urban soils used for
recreational purposes or vegetables recreational purposes or vegetables
production.production.
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Ag As Bi Cd Co Cr Cu Hg In Ni Pb Sb Se Sn Th Tl U Zn
ME
UM
ContextContext
•• Ratio of Ratio of UrbanUrban vs vs RegionalRegional agricultural agricultural topsoilstopsoils
•• Ratio of Ratio of UrbanUrban vs vs Local agricultural Local agricultural topsoilstopsoils
METALEUROP (Pb smelter)
UMICORE (Zn smelter)
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Ag As Bi Cd Co Cr Cu Hg In Ni Pb Sb Se Sn Th Tl U Zn
ME
UM
(Douay et al. 2008)
7
Lead blood level (> 100 µg L-1)
� 10 to 15 % of children (2 to 4 years old, from 1994 to 2002)
� up to 30 % under the prevailing winds
� 2.4 % in 2004 after smelter closedown
But the actual mean lead blood level is still over the national mean value (42 µg L-1 instead of 27 µg L-1 respectively)
ContextContext
AimsAims
••Evaluate Bioaccessibility of Evaluate Bioaccessibility of CdCd, , PbPb and Zn in and Zn in
urban soils for human health risk assessmenturban soils for human health risk assessment
••Differentiate bioaccessibility between smeltersDifferentiate bioaccessibility between smelters
••Understand the impact of soils Understand the impact of soils physicophysico--chemical chemical
parametersparameters
••Predict Bioaccessibility with multiple parameter Predict Bioaccessibility with multiple parameter
equationsequations
MaterialsMaterials and and methodsmethods27 urban topsoils were sampled
•20 soils
around
Metaleurop
Nord (ME)
•7 soils around
Umicore (U)
•12 lawns and
15 kitchen
gardens
MaterialsMaterials and and methodsmethods
•Pooled (5 to 13 elementary samples)
topsoil samples (0-25 cm) taken with a
stainless steel auger.
•Total Cd, Pb, Zn concentrations, in vitro
bioaccessibility tests, CEC, pH,
Carbonates, Organic matter, etc.
MaterialsMaterials and and methodsmethods
30.86.35.217.2cmol+ kg-1CEC
2.6800.1040.7110.912g kg-1P2O5
8.166.670.417.42g kg-1Total CaCO3
12313.730.856.6g kg-1Total nitrogen
101.51.033.429.2g kg-1Organic carbon
8.26.70.47.4pH
62.91311.526.1%Sand
69.927.49.553.1%Silt
28.88.15.420.8%Clay
MaxMinSDMean
•• PhysicoPhysico--chemicalchemical parametersparameters
MaterialsMaterials and and methodsmethods
6908.2325.91761.61941.2mg kg-1Total Zn
3025.695.1760.5983.8mg kg-1Total Pb
31.433.158.3914.96mg kg-1Total Cd
MaxMinSDMean
•• PhysicoPhysico--chemicalchemical parametersparameters
MaterialsMaterials and and methodsmethods•• In vitroIn vitro Bioaccessibility test (following Bioaccessibility test (following
BARGE UBM protocol)BARGE UBM protocol)
0.6 g soil
............................................................ ........................
+ 9 mL Saliva
+ 13.5 mL Gastric juice pH = 1.2 - 1.7
....................................
(pH = 6.5+_ 0.5)
Manualshaking
5 - 15 min
Chyme
..........................Residual soil
1h00 - 37°C
End-over-endrotation
Centrifugation3000 g - 5 min
Gastric extraction
Filtration 27µm(Whatman n°41)
Analysis AAS
Gastro-intestinal
extraction
+ 27 mL jus Duodenal+ 9 mL Bile
Centrifugation3000 g - 5 min
End-over-endrotation
4h00 - 37°C
Residual soil
..............Chyme
............
(pH = 6.3+_ 0.5)
Filtration 27µm(Whatman n°41)
Analysis AAS
............
ResultsResults
•• ReferenceReference NIST 2710NIST 2710
Total (mg kg-1)
(Ellickson et al., 2001) (Denys et al., 2007)(Oomen
et al.,2004)This study
Gastric Intestinal Gastric Intestinal Intestinal Gastric Intestinal
Cd 21,8 55-65 57.1 ±±±±2.8 27.2 ±±±± 8.3
Pb 5532 76.1 ± 11 10.7 ± 2.3 79 ± 4 25 ± 1 30-35 55 ±±±± 6.7 30.6 ±±±± 2.5
Zn 6952 20.5 ±±±± 3.8 11.1 ±±±± 1.2
ResultsResults•• Percentage of bioaccessible fraction of Percentage of bioaccessible fraction of CdCd, ,
PbPb and Zn expressed as a percentage of and Zn expressed as a percentage of total concentration in soil. total concentration in soil.
46.663.258.684.676.180.9Max
8.413.716.216.632.857.1Min
10.411.410.317.010.66.5SD
23.032.031.247.261.568.1Mean
ZnPbCdZnPbCd
Gastro-intestinalGastric
Results
• No clear differences of bioaccessibility (related to total concentration) among smelters
y = 0.4201x
R2 = 0.9028
y = 0.2919x
R2 = 0.8502
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Cd
Cd total (mg/kg)
Cd b
ioaccessib
le (
mg/k
g)
y = 0.3812x
R2 = 0.9217
y = 0.3503x
R2 = 0.8654
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1200
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Pb total (mg/kg)
Pb b
ioaccessib
le (
mg/k
g)
y = 0.3827x
R2 = 0.9267
y = 0.2869x
R2 = 0.8358
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500
1000
1500
2000
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3000
0 1000 2000 3000 4000 5000 6000 7000 8000
Zn total (mg/kg)
Zn b
ioaccessib
le (
mg/k
g)
Pb
Zn
Umicore
Metaleurop
ResultsResults
•• Relationships Relationships between between bioaccessible bioaccessible CdCd, , PbPb and Zn and total and Zn and total concentrations in concentrations in soils. soils.
Cd
y = 0.6928x - 0.1677
R2 = 0.9645
y = 0.3734x - 0.7023
R2 = 0.8141
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Cd total (mg kg -1)
Cd
bio
accessib
le (
mg
kg
-
1)
Zny = 0.6738x -212.79R2 = 0.9376
y = 0.4159x - 226.97
R2 = 0.9474
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3500
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4500
5000
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Zn total (mg kg -1)
Zn
bio
accessib
le (
mg
kg
-1)
Pby = 0.626x - 4.3255
R2 = 0.9584
y = 0.3907x - 49.419
R2 = 0.8896
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Pb total (mg kg -1)
Pb
bio
accessib
le (
mg
kg
-1)
R²=0.89
R²=0.81
R²=0.95
Gastric
Gastro-intestinal
Results
P<0.0010.975Bioacc Zn=0.412*[Zntot]-14.58*[Clay]-
86.42*[P2O5]-1.59*[CaCO3]+208.5
Zn
P<0.0010.944Bioacc Pb=0.395*[Pbtot]-1.04*[CaCO3]-
24.92*[Ntot]-81.75*pH+658.51
Pb
P<0.0010.87Bioacc Cd= 0.414*[Cdtot]-0.140*[CEC]-
0.009*[CaCO3]-0.45*[P2O5]+1.77
Cd
R²Equation
• Relationship between predicted bioaccessible
concentrations of Cd, Pb and Zn and soil parameters
given by stepwise regression models.
R²=0.89
R²=0.81
R²=0.95
DiscussionDiscussion
•• HOWEVER... As shown by Denys and coHOWEVER... As shown by Denys and co--authors (2007) carbonates can be positively authors (2007) carbonates can be positively related with bioaccessibility (PbCOrelated with bioaccessibility (PbCO33))
•• Urban Urban vsvs. minig soils behave differently (Pb . minig soils behave differently (Pb bioaccessibility between 40bioaccessibility between 40--84% and 84% and 1010--60% in 60% in CabocheCaboche and coand co--authors presentation Wed authors presentation Wed a.ma.m).).
•• Stepwise multiple regression showed that total Stepwise multiple regression showed that total
concentration was positively correlated to concentration was positively correlated to
bioaccessibility and bioaccessibility and PP22OO55, CEC, Clay, pH or , CEC, Clay, pH or
CaCOCaCO33 where negatively related.where negatively related.
ConclusionConclusion
•• Real importance of the source Real importance of the source
of contamination (speciation) and of contamination (speciation) and
the receiving matrix (soil quality)the receiving matrix (soil quality)
Post Doctoral position Post Doctoral position
availableavailableOral bioavailability assessment Oral bioavailability assessment
of trace elements in soils and of trace elements in soils and
dust from an area heavily dust from an area heavily
contaminated by a former lead contaminated by a former lead
smeltersmelter
ThankThank youyou for for youryour attention !attention !