1. 16/10/2013
Inter‐ and intra‐individual variability in biomarker
values over a continuous six‐day sampling period
Funded by:

2. Introduction
Concentration
Concentration
Long
t1/2
High
Exposure
frequency
Short
Concentration
Time
Concentration
Time
Low
Time
Time
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© 2013, VITO NV
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3. Introduction
Concentration
Concentration
Long
t1/2
High
Exposure
frequency
Short
Concentration
Time
Concentration
Time
Low
Time
Time
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4. Project outline
» CEFIC‐HBM4 project structure
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5. Project results
» WP3: Human Biomonitoring study
An HBM study will be set up to provide fit‐for‐purpose data for validation of
the TK‐model. A small number of participants will be asked to collect all urine
voids over the period of a week. Biomarker data will be used to identify how
urine collection frequency affects the determination and interpretation of
biomarker measurements, and to propose optimal sampling strategies in
function of chemical specific characteristics.
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6. WP3: Human biomonitoring study
» Outline:
8 individuals were recruited
All urinations were completely collected over a six‐day period
Exposure to personal care products (PCPs) was targeted
Diary with information on food consumption and use of personal care
products (at 30 minute intervals)
» Biomarkers included:
» 4 Metals (As, Cd, Mn, Ni)
» 15 Organic compounds (9 parabens, triclosan, triclocarban,
Benzophenon 1‐3‐8, BPA)
» Creatinin, specific gravity
»
»
»
»
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© 2013, VITO NV
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7. WP3: Human biomonitoring study
» Outline:
» Exposure to PCPs was based on the ingredient list published on
packages:
Toothpaste
Day cream
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8. WP3: Human biomonitoring study
» Exposure to personal care products (PCPs):
» Intake moment: inventory of personal care products used
» Two sets of products:
» Containing target substances (D‐2 to D1 and D4 to D6)
» Free of target substances (D2 and D3)
Product use with
target substances
Product use without
target substances
Urine collection
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© 2013, VITO NV
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9. WP3: Human biomonitoring study
» Activity diary:
» Included application of PCPs and food consumption
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10. WP3: Human biomonitoring study
» 8 individuals participated
Participant Participant Participant Participant Participant Participant Participant Participant
1
2
3
4
5
6
7
8
Gender
Female
Male
Female
Male
Female
Male
Female
Male
Age
31
38
31
40
58
58
66
66
Length (cm)
170
190
167
184
172
189
163
178
Weight (kg)
58
92
57
85
66
95
63
78
Profession
Teacher
Civil
servant
Quality
Quality
control
manager
Civil
servant
Civil
servant
Civil
Civil
servant
Retired
Retired
Smoking
No
No
No
No
No
Yes
No
No
Dietary
supplements
No
No
No
No
Yes
No
No
No
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© 2013, VITO NV
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11. WP3: Human biomonitoring study
» Urine collection parameters
» In total, 352 samples (not one reported missing, 1 sample incomplete)
Participant Participant Participant Participant Participant Participant Participant Participant
1
2
3
4
5
6
7
8
# Samples
43
46
40
45
65
34
39
40
Total volume (g)
7748,1
13987,8
7621,4
21047,5
10273,7
8244,9
12541,9
11101,1
Smallest sample (g)
15,8
73,3
40,4
82,9
6,0
93,4
21,4
67,4
Largest sample (g)
774,8
827,7
408,1
986,3
450,6
372,3
781,9
627,0
Size ratio (L/S)
49,0
11,3
10,1
11,9
75,1
4,0
36,5
9,3
1,04
1,38
1,19
2,41
1,29
0,68
1,41
1,21
24,5
12,4
11,7
16,1
90,1
6,2
15,4
10,8
Avg urine flow rate
(g/kg b.w./hour)
Urine flow rate ratio
(L/S)
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12. WP3: Human biomonitoring study
» Biomarker measurements ‐ Metals:
» Arsenic (t1/2 ≈ 4 days*)
* Hughes (2006)
At 18:00
Scampi’s for dinner
Hours since start collection
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© 2013, VITO NV
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13. WP3: Human biomonitoring study
* ATSDR (2008)
» Biomarker measurements – Metals
» Cadmium (t1/2 ≈ 6‐38 years*) – Environmental exposure,
smoking
» Clear diurnal cycle in Cd‐excretion…
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14. WP3: Human biomonitoring study
» Biomarker measurements – Metals
» Cadmium – diurnal pattern
0:00-6:00
6:00-10:00
10:00-14:00
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© 2013, VITO NV
14:00-18:00
18:00-0:00
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15. WP3: Human biomonitoring study
» Biomarker measurements – Organic components
» 15 different biomarkers measured
Parabens
Compound
% < LOQ
Methyl
0,0 %
Butyl
(LOQ=0,5 µg/l)
(0,0 % – 0,0 %)
(LOQ=0,5 µg/l)
Ethyl
(0,0 % – 31,1 %)
(LOQ=0,5 µg/l)
Iso‐propyl
(LOQ=0,5 µg/l)
Propyl
(LOQ=0,5 µg/l)
Iso‐butyl
(LOQ=0,5 µg/l)
(range)
6,8 %
100 %
29,3 %
(0,0 % – 76,5 %)
Compound
Benzyl
(LOQ=0,5 µg/l)
Pentyl
(LOQ=0,5 µg/l)
Heptyl
(LOQ=0,5 µg/l)
Benzophenones
% < LOQ
Compound
73,9 %
BP 1
95,7 %
100 %
(LOQ=0,5 µg/l)
BP 3
(LOQ=0,5 µg/l)
BP 8
(LOQ=0,5 µg/l)
Others
% < LOQ
Compound
86,6 %
Bisphenol A
29,8 %
(0,0 % – 91,2 %)
100 %
(LOQ=0,5 µg/l)
Triclosan
(LOQ=0,5 µg/l)
Triclocarban
(LOQ=0,5 µg/l)
% < LOQ
26,2 %
(1,1 % – 52,9 %)
20,5 %
(0,0 % – 93,3 %)
100 %
100 %
100 %
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© 2013, VITO NV
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16. WP3: Human biomonitoring study
» Biomarker measurements – Organic components
Day cream +
shower gel +
» Methylparaben exposure
body lotion
(D5, 16:30)
Day cream
(D0, 22:30)
Day cream
(D4, 7:00)
Day cream
(D1, 23:00)
Day cream
(D4, 23:00)
Hours since start of urine collection
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17. WP3: Human biomonitoring study
» Biomarker measurements – Organic components
Day cream +
shower gel +
» Methylparaben exposure
body lotion
(D5, 16:30)
Day cream
(D0, 22:30)
Day cream
(D4, 7:00)
Day cream
(D1, 23:00)
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© 2013, VITO NV
Day cream
(D4, 23:00)
Shampoo +
conditioner +
day cream +
showergel
(D6, 8:30)
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18. WP3: Human biomonitoring study
» Biomarker measurements – Organic components
» Triclosan exposure
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© 2013, VITO NV
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19. WP3: Human biomonitoring study
» Biomarker measurements – Organic components
» Triclosan exposure
» Effect of toothpaste brand !
time lag
time lag
10-fold decline over 42 hours ~ 12.5 hr HL, similar to 11h in literature*
16/10/2013
© 2013, VITO NV
* Sandborgh‐Englund et al, 2006
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20. WP3: Human biomonitoring study
» Inter‐ versus intra‐individual variability
» Log‐transformation measurements
» One‐way random effects ANOVA
» ICC < 0,4 ≈ poor reproducibility
» 0,4 < ICC < 0,75 ≈ fair to good reproducibility
» ICC > 0,75 ≈ excellent reproducibility
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© 2013, VITO NV
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21. WP3: Human biomonitoring study
» Biomarker measurements – Metals
» Inter‐ versus intra‐individual variability
Arsenic
Cadmium
Manganese
Nickel
Creatinin
Specific gravity
Expressed as ng/l
Between individual variability
5,26
28,13
24,49
6,60
10,38
0,0039
Within individual variation
45,40
32,97
121,9
31,89
40,98
0,0199
ICC
0,104
0,460
0,167
0,207
0,253
0,196
Expressed as ng/g creatinin
Between individual variability
6,25
20,24
29,18
14,47
Within individual variation
24,25
6,76
74,92
6,87
ICC
0,205
0,750
0,280
0,678
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© 2013, VITO NV
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22. WP3: Human biomonitoring study
» Biomarker measurements – Metals
» Inter‐ versus intra‐individual variability
» High ICC for Cadmium…
Ng/l
8 participants
58-66 years
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© 2013, VITO NV
0,460
0,750
Age 30‐40
30-40 years
Ng/g creatinin
0,219
0,075
Age 58‐66
0,407
0,328
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23. WP3: Human biomonitoring study
» Biomarker measurements – Organic compounds
» Inter‐ versus intra‐individual variability
Methyl paraben: ICC = 0.52
Triclosan: = 0.15 0.92
BPA: ICC ICC =
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© 2013, VITO NV
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24. Conclusions
» Analyses still in progress
» Use of PCP containing target analytes can be detected in urinary
profiles
» In many cases rapid rise and subsequent decreases
» Factors influencing variation in spot sample concentrations:
» Intra‐individual
» Elimination half‐life in relation to intervals between exposure events
» Variation in exposure rates
» Inter‐individual
» Variation in exposure rates
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© 2013, VITO NV
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25. Acknowledgments
» The 8 participants: for collecting urine, carrying around empty and full jars,
and filling in the questionnaires;
» The project team:
» HSL (UK): Nick Warren, Kevin McNally, John Cocker, Kate Jones
» Summit Toxicology (USA): Sean Hays, Lesa Aylward, Chris Kirman
» Cranfield University (UK): Len Levy, Ruth Bevan
» IPA ‐ Ruhr‐University of Bochum (DE): Holger Koch
» CEFIC: for financial support under the Long Range Initiative (CEFIC‐HBM4)
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