Slide 1 Using Biomonitoring Levels from the National...
Transcript of Slide 1 Using Biomonitoring Levels from the National...
Slide 1
Using Biomonitoring Levels from the
National Health and Nutrition
Examination Survey to Evaluate
Exposures from Hazardous Waste Sites
Presented at the
Environment, Energy & Sustainability Symposium
May 2010
Greg Zarus and Tonia BurkDivision of Health Assessment and Consultation
Agency for Toxic Substances and Disease Registry (ATSDR)
(770)488-0764
The findings and conclusions in this presentation are those of the author and do not necessarily represent the views of the
Agency for Toxic Substances and Disease Registry /Centers for Disease Control and Prevention.
Slide 2
ATSDR
• ATSDR serves the public by using the
best science to prevent harmful
exposures and diseases related to toxic
substances.
• Being formed by CERCLA, ATSDR has a
residential-exposure focus (rather than
occupational focus).
Slide 3
Outline
• Overview of biomonitoring
• Review of NHANES studies
• Performing biomonitoring studies
• Summary
Slide 4
Why Use Biomonitoring?
To determine if environmental exposures are
significant . For example,
- Health: Are there clinically relevant exposures?
- Statistical: Does exposures to chemicals in the
environment cause people to have higher than
normal levels?
- Hobbies /occupation: Are there other TCE
exposures to worry about?
Slide 5
Continuum for Relating
Environmental Contamination
with Clinical DiseaseS
COURCE
ONTAMINATION
TH
E
OTAL
UMAN
XPOSURE
ID
NTERNAL
OSE
BE
D
IOLOGICALLY
FFECTIVE
OSE
EB
E
ARLY
IOLOGICAL
FFECT
ET
NVIRONMENTAL
RANSPORT
AS /
F
LTERED
TRUCTURE
UNCTION
CD
LINICAL
ISEASE
T D EARGET OSE VALUATION
E E
XP
OS
UR
EV
AL
UA
TIO
N
H E
EE
AL
TH
FF
EC
TS
VA
LU
AT
ION
Slide 6
Who Uses Biomonitoring?
ATSDR: To understand community
exposure to site-specific chemicals
NCEH: To understand the distribution of
chemicals across the nation and study
some unique exposures
Slide 7
NHANES Overview
NHANES tests about 2500 people randomly to represent the US population every 2 yrs
Media sampled: urine, blood, serum, exhaled breath
Problematic media: hair, nails
Analytics:
Speciation of metals
Degradation products of VOCs
There is NO HEALTH ENDPOINT ASSOCIATION to most biomonitored levels, but ATSDR’s Tox Profiles provide biomonitored levels from other studies
Slide 8
VOC Sources
Benzene (at defense and other sites)
- Fuel
- Household paints and degreasers
PCE (at defense and other sites)
- Recently dry cleaned fabrics
- Household adhesives, degreasers, stain
remover
TCE (under most air fields and as decay of PCE)
- Household products
- Household solvents, rust remover, sealant
Slide 9
VOC Comparisons
Air (µg/m3) Blood (ng/mL)
Indoor Outdoor 50th% 95th%
Benzene 29 F 9.6 B .030* .027** .320* .260**
TCE 6.5 B 5 C ND* ND** ND* ND**
PCE 25.4 B 10.4 B ND* ND** .190* .140**
F =fuel oil heated homes * NHANES 2001-2
B=Bldg Assess. Survey Eval. ** NHANES 2003-4
C = Control home database NYSDOH LOD ~ 0.2 ng/mL
Ball park: 100 to 1 for 95th and 1000 to 1 for 50th
Slide 10
PCE Comparisons
Air (µg/m3) Blood (ng/mL)
Indoor Outdoor 50th% 95th%
PCE (all) 25.4 B 10.4 B ND (<0.02)** 0.140**
PCE
Case
study
537000 1408
B=Bldg Assess. Survey Eval. * NHANES 2001-2
LOD ~ 0.2 ng/mL ** NHANES 2003-4
Case study suggests similar ratio for high exposures: ~400 to 1Ref: http://ehp.niehs.nih.gov/members/1998/106p573-580pleil/pleil-full.html
Peil et al 1998; Gobba et al. 2003
Slide 11
Benzene Exposuresconfounders with assessing defense sites
Cigarettes
Car Exhaust
PersonalActivities
Home Sources
ETS
Industry
Ref: Wallace 2010;
ETS =Environmental Tobacco Smoke
Slide 13
Biomarker
Urinary Arsenic in ug/L easy to obtain sample
readily available references
Population data 50% (95% CI) 95% (95% CI)
Tot As 7.70 (6.70-8.70) 65.4 (48.7-83.3)
As-Betaine 1.00 (0.700-1.30) 35.0 (27.6-44.6)
Inorg-As 6.0 (5.4-6.1) 18.9 (15.8-22.9)
DMA 3.90 (3.00-4.00) 16.0 (13.0-17.8)
Slide 14
Arsenic (recent exposure)
0
10
20
30
40
50
60
70
80
90
Concentr
atio
n
Arsenic Levels* (95th percentile with 95% confidence interval error bars)
* NHANES Data 2005
µg/L in urine● µg/g creatinine in urine
Slide 15 Confounding Sources of
Arsenic to Consider
• Wood preservatives
• Pesticides
• Arsenic containing herbal medicines
• Parental occupational exposure
• Hobbies
• Consumption of seafood
• Pica (soil eating) behavior
Slide 16
Problems with Using
Biomarkers for Arsenic
• Does not identify source of
exposure
• Limited to documenting recent
exposures
• Can not correlate exposure with
health effect (as with Hg and Pb)
Slide 17
Lead
However:
•Primary routes of exposure: ingesting water, dust,
paint chips, inhaling dust
•Primary sources of exposure: lead based paint
•Analysis: isotopic analysis – 204Pb, 206Pb, 207Pb, 208Pb
– geography dependent
• exclusionary but not real fingerprinting
ATSDR often assesses lead levels at shooting ranges on defense sites.
Slide 18
Lead
0.20
1.20
2.20
3.20
4.20
5.20
6.20
Concentr
atio
n
Lead Levels* (95th percentile with 95% confidence interval error bars)
* NHANES Data 2005
µg/dL in blood
µg/L in urine
● µg/g creatinine
Slide 19
Blood Lead is a Good
Biomarker
• Requires only small amount of sample
• Lead remains stable when blood is stored
• Documented reference range
• However, blood sampling is more invasive than urine sampling
Slide 20
Cadmium
However:
• Common environmental
contaminant
• Higher in smokers
ATSDR often assesses cadmium exposures associated with
corrosion –treatment at defense sites.
Slide 21
Cadmium
0.20
0.40
0.60
0.80
1.00
1.20
1.40
1.60
1.80
Concentr
atio
n
Cadmium Levels* (95th percentile with 95% confidence interval error bars)
* NHANES Data 2005
µg/dL in blood
µg/L in urine
● µg/g creatinine
Slide 22
Mercury
However:
• Naturally occurring and coal power plant
emissions
• Methylated in water and bioaccumulates in
seafood and shellfish
ATSDR had identified that one of the main contributors to mercury
exposures at military bases in the past was due to the use of solid waste
incinerators (also a problem common at municipal landfills).
Slide 23
Total Blood Mercury (ug/L)*
50% 95%
Mercury 0.800 (0.760-0.900) 4.76 (4.40-5.20)
* Non-hispanic blacks had the highest levels except in the 70+ age category
* NHANES data 2003-2006
* Caldwell et al. 2009b
Slide 24
Biomonitoring Study Considerations for
DoD Sites
• Questionnaires- Dietary contributors
- Seafood for arsenic and mercury
- Household exposures
- Hobbies, household products (cleaners, drycleaning)
- Dust (lead based paint)
- Drinking water (lead containing pipes, naturally occuring arsenic)
- Occupational exposures
- Petroleum product exposures
- Solvent exposures
Slide 25
Biological Levels & Confounders
• Age
• Sex
• Genetics
• Lifestyle choices- Alcohol use
- Liver enzyme review
- Smoking
- Excessive UV exposure
Slide 27
References• Benjamin C. Blount, Robert J. Kobelski, David O. McElprang,
David L. Ashley, John C. Morrow, David M. Chambers and Frederick L. Cardinali. Quantification of 31 volatile organic compounds in whole blood using solid-phase microextraction and gas chromatography–mass spectrometry. Journal of Chromatography B Volume 832, Issue 2, 7 March 2006, Pages 292-301