slide 1 using biomonitoring levels from the national...

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.

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).

Outline

• Overview of biomonitoring

• Review of NHANES studies

• Performing biomonitoring studies

• Summary

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?

Continuum for Relating

Environmental Contamination

with Clinical DiseaseS

COURCE

ONTAMINATION

TH

E

OTAL

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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

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

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

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

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

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

http://ehp.niehs.nih.gov/members/1998/106p573-580pleil/pleil-full.html





Benzene Exposuresconfounders with assessing defense sites

Cigarettes

Car Exhaust

PersonalActivities

Home Sources

ETS

Industry

Ref: Wallace 2010;

ETS =Environmental Tobacco Smoke

Arsenic Sources at Defense Sites

• Chemical weapons

• Pesticides

• Herbicides

• Railways

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)

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

Confounding Sources of

Arsenic to Consider

• Wood preservatives

• Pesticides

• Arsenic containing herbal medicines

• Parental occupational exposure

• Hobbies

• Consumption of seafood

• Pica (soil eating) behavior

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)

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.

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

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

Cadmium

However:

• Common environmental

contaminant

• Higher in smokers

ATSDR often assesses cadmium exposures associated with

corrosion –treatment at defense sites.

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

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).

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

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

Biological Levels & Confounders

• Age

• Sex

• Genetics

• Lifestyle choices- Alcohol use

- Liver enzyme review

- Smoking

- Excessive UV exposure

Thanks to Tonia

Tonia Burk, PhDEnvironmental Health Scientist

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

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