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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
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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)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.
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.
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 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?
Continuum for Relating Environmental Contamination with Clinical Disease
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 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 F =fuel oil heated homes * NHANES 2001-2 B=Bldg Assess. Survey Eval. ** NHANES 2003-4 CHD –Control home database NYSDOH LOD ~ 0.2 ng/mL Ball park: 100 to 1 for 95th and 1000 to 1 for 50th
PCE Comparisons 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 1 Ref: http://ehp.niehs.nih.gov/members/1998/106p573-580pleil/pleil-full.html Peil et al 1998; Gobba et al. 2003
Benzene Exposuresconfounders with assessing defense sites Ref: Wallace 2010; ETS =Environmental Tobacco Smoke
Arsenic Sources at Defense Sites • Chemical weapons • Pesticides • Herbicides • Railways
BiomarkerUrinary Arsenic in ug/L easy to obtain samplereadily available references
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 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
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
Cadmium However: • Common environmental contaminant • Higher in smokers ATSDR often assesses cadmium exposures associated with corrosion –treatment at defense sites.
Mercury 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
Total Blood Mercury (ug/L)* * 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, PhD Environmental 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