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 Burk
Division of Health Assessment and Consultation
Agency for Toxic Substances and Disease Registry (ATSDR)
(770)
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.

2. The findings and conclusions in this presentation have not been formally disseminated by the Agency for Toxic Substances and Disease Registry and should not be construed to represent any agency determination or policy.

3. 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).

4. Outline Overview of biomonitoring Review of NHANES studies
Performing biomonitoring studies
Summary

5. Why Use Biomonitoring?
To determine if environmental exposures are significant . For example,
Health: Are there clinically high 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?

6. Continuum for Relating Environmental Contamination with Clinical Disease

7. 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

8. NHANES Overview
NHANES tests about 2500 people randomly to represent the US population
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

9. 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

10. VOC Comparisons Air (µg/m3) Blood (ng/mL) Benzene 29 F 9.6 B
Indoor
Outdoor
50th%
95th%
Benzene
29 F
9.6 B
.030* .027**
.320* **
TCE
6.5 B
5 C
ND* ND**
ND* ND**
PCE
25.4 B
10.4 B
.190* .140**
F =fuel oil heated homes * NHANES
B=Bldg Assess. Survey Eval ** NHANES
CHD –Control home database NYSDOH LOD ~ 0.2 ng/mL
Ball park: 100 to 1 for 95th and 1000 to 1 for 50th

11. PCE Comparisons Air (µg/m3) Blood (ng/mL) PCE (all) 25.4 B 10.4 B
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
LOD ~ 0.2 ng/mL ** NHANES
Case study suggests similar ratio for high exposures: ~400 to 1
Ref:
Peil et al 1998; Gobba et al. 2003

12. Benzene Exposures confounders with assessing defense sites
Ref: Wallace 2010;
ETS =Environmental Tobacco Smoke

13. Arsenic Sources at Defense Sites
Chemical weapons
Pesticides
Herbicides
Railways

14. 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 ( )
65.4 ( )
As-Betaine
1.00 ( )
35.0 ( )
Inorg-As
6.0 ( )
18.9 ( )
DMA
3.90 ( )
16.0 ( )

15. Arsenic (recent exposure)

16. Confounding Sources of Arsenic to Consider
Wood preservatives
Pesticides
Arsenic containing herbal medicines
Parental occupational exposure
Hobbies
Consumption of seafood
Pica (soil eating) behavior

17. 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)

18. Lead
ATSDR often assesses lead levels at shooting ranges on defense sites.
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

19. Lead

20. Blood Lead is a Good Biomarker
Requires only small amount of sample
Lead remains stable when blood is stored
Documented reference range
However, blood is more invasive than urine

21. Cadmium
ATSDR often assesses cadmium exposures associated with corrosion –treatment at defense sites.
However:
Common environmental contaminant
Higher in smokers

22. Cadmium

23. Mercury However: Naturally occurring and coal power plant emissions
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).
However:
Naturally occurring and coal power plant emissions
Methylated in water and bioaccumulates in seafood and shellfish

24. Total Blood Mercury (ug/L)*
50%
95%
Mercury
0.800 ( )
4.76 ( )
* Non-hispanic blacks had the highest levels except in the 70+ age category
* NHANES data
* Caldwell et al. 2009b

25. 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

26. Biological Levels & Confounders
Age
Sex
Genetics
Lifestyle choices
Alcohol use
Liver enzyme review
Smoking
Excessive UV exposure

27. Thanks to Tonia
Tonia Burk, PhD
Environmental Health Scientist

28. 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