Biomonitoring IIEnviroChem Connections

Mini-Talk 1 on CDC’s 3rd Report

Suzanne Snedeker

Cornell University

Sprecher Institute for

Comparative Cancer Research

Biomonitoring

What is biomonitoring? The direct measurement of chemicals

or metabolites in humans

Reflects “internal dose” - what the body has actually taken up

Reflects all sources of exposure

Biomonitoring

Source of Samples Blood (whole or serum) Urine (for chemicals rapidly excreted) Adipose tissue (fat) Breast milk Toenails or hair Exhaled breath

CDC 3rd Report - NHANES

National Health and Nutrition Examination Survey (NHANES)

Done every 2 years by the CDC Surveys 5,000 people in the U.S.

Home interview Physical examination in “mobile unit” Obtain blood sample (over 1 year) Obtain urine sample (over 6 years) Analysis done on a random sample

CDC 3rd Report-Scope of study design

148 chemicals or their metabolites Three age ranges:

6-11 years, 12-19 years, 20-59 years 1-5 years for some chemicals [lead]

Three ethnic / racial groups Mexican Americans Non-Hispanic Blacks Non-Hispanic Whites

Types of chemicals

Metals Organochlorine insecticides Organophosphate insecticides Pyrethroid Pesticides Herbicides Tobacco smoke (cotinine)

Types of Chemicals

Phthalates Phytoestrogens PAHs (polyaromatic hydrocarbons) PCBs (polychlorinated biphenyls) PCDDs (polychlorinated dibenzo-p-dioxins) PCDFs (polychlorinated dibenzofurans)

Environmental Public Health Tracking- What it can provide

Direct assay of chemical body burden from all sources of exposure

Tracks trends in exposures over time Identifies at-risk populations Establishes “reference ranges” for

chemicals for which we have little/no data Helps evaluate if prevention efforts work Provides direction for further research and

monitoring efforts

Major findings - New data

First-time exposure data for 38 chemicals - “reference ranges”

Aldrin, endrin, and dieldrin Some PAHs (benzo[a]pyrene) Additional phthalate metabolites Additional dioxins, furans and PCBs Additional insecticides and herbicides

Photo:www.cdc.gov/nceh/dls/national_biomonitoring_program.htm

Major findings - Blood Lead

Blood lead levels continue to decline There is no “safe” level of blood lead Percentage of children 1-5 years old

with blood lead levels at or above 10 ug/dl 1976-1980 88.2% 1988-1991 8.6% 1991-1994 4.4% 1999-2002 1.6%Photos: www.cdc.gov/nceh/dls/lead.htm

Major findings-Urinary Cadmium (Cd)

5% of US population has levels above

1 g Cd/g creatinine (? kidney effects ?) Significance of Cd findings for breast

cancer risk is not known, but provides much needed exposure data.

Cd can support the growth of breast tumor cell lines; may affect mammary development (lab animal studies)

Major findings - Phthalates

Phthalate metabolites New, more sensitive biomarkers Data on exposure at different ages For most phthalate metabolites, levels

in the urine of children 6-11 years of age were higher than levels in adults (sometimes twice as high)

Levels in US population at or higher than levels reported in Germany

Major findings -Organochlorine pesticides

p,p’-DDE Levels in Mexican Americans

Two-fold high than non-Hispanic blacks Three-fold higher in non-Hispanic whites

Other organochlorines Many were below the limits of detection Including: DDT, aldrin, endrin, dieldrin,

heptachlor epoxide, mirex)

Major findings - Smoking

Environmental tobacco smoke Dramatic decrease in exposure to

environmental tobacco smoke in non-smokers (median cotinine levels)

Compared to 1988-91 data, saw: 68% decrease in children 69% decrease in adolescents 75% decrease in adults

Photo: www.cdc.gov/nceh/dls/tobacco_smoking.htm

New chemicals to be monitored in future reports

Metals (arsenic and methyl mercury) Volatile Organic Chemicals (VOCs) Polybrominated compounds Phenols (bisphenol A, nonylphenol

and octylphenol – estrogen mimics) Perfluorinated compounds Polychlorinated biphenyls (PCBs)

New chemicals to be monitored in future reports

Additional pesticides in these classes Organochlorine pesticides Organophosphate pesticides Chloroacetanilide herbicides

Acetochlor and metolachlor metabolites

PyrethrinsPhoto: www.cdc.gov/biomonitoring/overview.htm

What the current CDC report does not provide

Levels by region (state, county, zip code) Seasonal variations in levels Environmental levels (air, water, food, soil) Duration or intensity of exposures Use of particular products Whether levels are associated with a

particular health effect

CDC - Spokes in the wheel Environmental Public Health Tracking

Biomonitoring program Provides state funding

Targeted research projects Improve infrastructure to

integrate biomonitoring and health indicator data

Develops new biomarkers Provides sample analysis for

breast cancer studies