Results from the

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Results from the Agricultural Health
StudyPesticide Exposure Study
Linda Sheldona, Kent Thomasa, Guadalupe Chapaa,
Sydney Gordonb Martin Jonesc, James Raymerd,
Dale Sandlere, Jane Hoppine Mustafa Dosemecif,
Aaron Blairf, and Michael Alavanjaf aNational
Exposure Research Laboratory, U.S. Environmental
Protection Agency bBattelle Memorial Institute,
cUniversity of Iowa, dRTI International
eNational Institute of
Environmental Health Sciences, fNational
Cancer Institute
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• PRESENTATION OVERVIEW
• Background of the Agricultural Health Study
• Purpose of the Pesticide Exposure Study
• Exposure Study Procedures
• Applicator Exposure Measurement Results
• Spouse and Child Measurement Results

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• AGRICULTURAL HEALTH STUDY RESEARCHERS
• NCI and NIEHS are leading the epidemiological
  study and investigations of cancer and
  non-cancer health outcomes
• University of Iowa Department of Epidemiology
  operates the Iowa AHS Field
  Station
• Battelle Center for Public Health Research and
  Evaluation operates the North Carolina AHS Field
  Station
• Westat operates the AHS Coordinating Center
• EPA and NIOSH are leading AHS exposure
  sub-studies
• Battelle, University of Iowa, and RTI
  International conducted the AHS Pesticide
  Exposure Study

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• AHS BACKGROUND
• The epidemiological study is designed to 
• Measure cancer and non-cancer health risks
  in the agricultural community
• Examine associations between use of
  agricultural chemicals, other exposures,
  and disease 
• Determine factors that promote good health

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• AHS PHASE I (1993 1997)
• Prospective cohort enrolled in Iowa and North
  Carolina
• 52,395 private licensed pesticide applicators
• 32,347 spouses of private pesticide
  applicators
• 4,916 commercial applicators (IA only)
• Questionnaires collected information about
  pesticide use, work practices, other exposures,
  lifestyle factors, and health.

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AHS PHASE II (1998 2004) Follow-up through
cancer registries and vital records
linkage 5-year follow-up questionnaire via
computer assisted telephone interview
(CATI) Update health status, exposures, and
lifestyle Buccal Cell Collection and Dietary
Health Questionnaire Nested studies of exposure
and specific health outcomes AHS PHASE III (2005
- 2008) Continued cancer and mortality
follow-up Follow-up telephone interview Cross
sectional and panel studies, nested case-control
studies
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• AHS RESULTS DISSEMINATION
• AHS Web Site
• www.aghealth.org
• Direct communication to study participants
• Fact sheets and other information distributed to
  and through Iowa and North Carolina Cooperative
  Extension Services
• Scientific and Informational Presentations
• Journal Publications

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AHS PESTICIDE EXPOSURE CLASSIFICATION
The AHS is examining possible links between
pesticide use and health risks Information on
use of up to 50 common insecticides, herbicides,
fungicides, and fumigants obtained from AHS
enrollment and take-home questionnaires current
and historical uses Information on work
practices collected from questionnaires

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AHS EXPOSURE CLASSIFICATION
1) Ever/Never Use of a Pesticide
2) Cumulative Exposure Years Used x
Days/Year




3) Adjusted Cumulative Exposure Years Used
x Days/Year x Intensity Score


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AHS EXPOSURE INTENSITY ALGORITHM
Intensity Score
(Mix Appl Repair) PPE
where,
Mix
Mixing Frequency of Pesticides (0, 3, 9)
Appl
Application Method (0 - 9)
Repair
Repair of Application Equipment (0, 2)

PPE
Personal Protective Equipment (0.1 - 1.0)
Dosemeci et al., Ann Occ Hyg, 462, 2002
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• AHS PESTICIDE EXPOSURE STUDY
• Overall Goal
  
• Measure exposure to applied pesticides for a
  subset of AHS applicators to evaluate and improve
  the AHS exposure algorithm
• Specific Objectives
• Measure exposure to target applied pesticides
• Compare measurements to algorithm exposure
  intensity scores
• Identify key exposure factors
• Assess potential spouse/child exposure to
  farm- applied pesticides

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• STUDY DESIGN OVERVIEW 
• Target pesticides 2,4-D and Chlorpyrifos
  
•   Eight exposure strata based on application
  method and PPE
• Applicators monitored on one day while using
  their normal procedures
• Observation of activities
• Dermal, personal air, urine samples
• Questionnaires after use
• Spouse and child biomarker measurement

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• PARTICIPANT SELECTION AND RECRUITMENT
• Sample Frame
• AHS cohort members completed AHS Phase I II
• Reside in one of 22 Iowa or 22 NC counties
• Previous use of a target chemical
• Eligibility Screening
• Telephone screening
• Eligible with planned use of a target chemical
• Recruitment
• In-home visit to discuss study
• Applicator, spouse, child consent/assent
• Schedule monitoring visits

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OVERALL MONITORING TOTALS
IA NC Total
Pesticide Applicators 84a 24
108 Spouses (urine) 38b 11
49 Children (urine) 9
3 12
a Includes 24 repeat monitoring visits for
applicators b Includes 8 repeat monitoring visits
for spouses
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NUMBER OF OBSERVATIONS IN EXPOSURE STRATA

• Broadcast Spray Liquid 2,4-D or Chlorpyrifos
• No gloves, no enclosed cab
  9
• No gloves, enclosed cab 9
• Gloves, no enclosed cab 14
• Gloves, enclosed cab 21
• In-Furrow Granular Chlorpyrifos
• No enclosed cab 7
• Enclosed cab 6
• Hand Spray Liquid 2,4-D
• No gloves 22
• Gloves 20

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MONITORING SCHEDULE

• Visit 1
• Provide urine sample containers discuss
  scheduling
• Visit 2
• Sample collection (dermal, air, urine)
• Observe activities
• Application questionnaire
• Visit 3
• Sample collection (urine pick-up)
• Activity questionnaire

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MEASUREMENTS

• Dermal Patches
• 10 Patches, sized proportionally to body area,
  under
• PPE and over clothing, combined for analysis
• Hand Wipe
• Combined wipes from 12 small areas on each hand
• Personal Air
• Personal monitor (pump and filter)
• Applicator Urine
• Pre-Application morning void
• Post-Application Composite (start of pesticide
  use
• through the following morning)
• Spouse and Child Urine
• Pre-Application morning void
• Post-Application morning void (2 days later)

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APPLICATOR MEASUREMENT RESULTS Comparison of
exposure measurements across eight exposure
strata Assessment of the relative contribution of
hand loading, body loading, and air exposures to
urinary biomarker levels Bivariate analyses for
gt80 pesticide use, work, and hygiene factor
variables selected results shown here
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Preliminary Results
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Preliminary Results
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Preliminary Results
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Preliminary Results
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Applicator Chlorpyrifos Levels (Geometric Means)
By Physical State (as applied)
a Measured as 3,5,6-trichloro-2-pyridinol (TCP)
metabolite b Near average pre-application
background levels of 9.8 ?g/L
Preliminary Results
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Exposure Pathway Model Results
Preliminary Results
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Hand Loading vs. Post-Application Urine
Concentration (For liquid products only)
Preliminary Results
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Applicator 2,4-D Levels (Geometric Means) By
Application Method
0.05 gt p gt 0.001 or p 0.001 for
significance of difference
Preliminary Results
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Applicator Post-Application 2,4-D Urine Levels
Regression with Selected Variables
0.1 gt p gt 0.05 0.05 gt p gt 0.001 p
0.001
Preliminary Results
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Applicator Post-Application 2,4-D Urine Levels
(Geometric Mean ug/L) for Selected Variablesa
a Minimum number in any cell 5 p 0.01 for
significance of difference
Preliminary Results
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Applicator Post-Application 2,4-D Urine Levels
(Geometric Mean ug/L) for Selected Variablesa
a Minimum number in any cell 5 0.05 gt p gt
0.01 or p 0.01 for significance of
difference
Preliminary Results
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Hand-Spray Applicator 2,4-D Levels (Geometric
Means) by Footwear Type
Preliminary Results
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Broadcast Spray Applicator 2,4-D Levels
(Geometric Means) by Tractor Cab Type
a Measurement result divided by kg of pesticide
active ingredient used
Preliminary Results
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Broadcast Spray Applicator 2,4-D Levels
(Geometric Means) by Enclosed Cab Variable
Preliminary Results
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FAMILY MEASUREMENT RESULTS Measurement of urinary
biomarkers for participating applicator family
members Relationships between spouse and
applicator urinary biomarkers Relationship
between spouse 2,4-D urine levels and applicator
work practices or household factors
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Preliminary Results
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SPOUSE AND APPLICATOR POST-APPLICATION URINE
2,4-D CONCENTRATIONS
Preliminary Results
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Spouses Post-Application 2,4-D Levels based on
Selected Applicators Work Practices
a Mann-Whitney U Non parametric comparison test
Preliminary Results
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Spouses Post-Application 2,4-D Levels Based on
Selected Household Activities
a Mann-Whitney U Non parametric comparison test
Preliminary Results
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Spouses Post-Application 2,4-D Levels Based on
Homes Distance from Pesticide Use
a Mann-Whitney U Non parametric comparison test
Preliminary Results
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APPLICATOR MEASUREMENTS
PRELIMINARY FINDINGS

• Large range in exposures for spray 2,4-D
  applicators in this study
• Lower exposures and range of exposures for
  chlorpyrifos applicators in this study
• Chlorpyrifos exposures for users of liquid
  products were much higher than those for users of
  granular products
• Significant differences in exposure were found
  between many exposure strata

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APPLICATOR MEASUREMENTS PRELIMINARY FINDINGS

• Differences in exposure for different application
  methods (hand spray gt broadcast gt in-furrow)
• Glove use was an important factor wearing
  protective gloves reduced urine levels 70
• Role of enclosed tractor cabs in reducing
  exposures is less clear for mixer/loader/applicato
  rs
• Significant associations between urine and dermal
  or air measures strongest for hand loading
• Several other factors appear to be important in
  increasing or decreasing exposures to 2,4-D

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• SPOUSE AND CHILD
• PRELIMINARY FINDINGS
• Urinary 2,4-D levels were low but measurable for
  a majority of the spouses and children of 2,4-D
  applicators (geometric means ?2 ug/L)
• One spouse reported directly handling a product
  containing 2,4-D and had the highest urine level
  (59 ug/L)
• Urinary TCP levels were measurable for the
  spouses and children of chlorpyrifos applicators
  but these levels were similar to those found in
  non-farm populations

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SPOUSE AND CHILD
PRELIMINARY FINDINGS Spouse and applicator
post-application urine 2,4-D levels were
significantly associated Some pesticide
applicator work practices were significantly
associated with spouse urine 2,4-D levels Some
hygiene and household (laundering work clothing,
removal of work boots, distance to fields) were
not associated with significantly higher
exposures to family members in this
study Further study is needed with more people
and for different chemicals

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• COMMUNICATION OF RESULTS
• Journal articles in preparation
• Plan for development of AHS/PES outreach
  materials (brochure and slide sets)
• Audience
• AHS participants
• Pesticide safety educators
• Cooperative Extension Services
• Pesticide users

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ACKNOWLEDGEMENTS Researcher
s at several organizations provided key
contributions to the AHS Pesticide Exposure Study
design and implementation EPA Ruth Allen
(OPP), Carry Croghan, Paul Jones AHS Federal
Investigators Cynthia Hines (NIOSH) NC AHS Field
Station Charles Knott and Joy Pierce (Battelle
CPHRE) IA AHS Field Station Charles Lynch and
Ellen Heywood (University of Iowa) Field Study
Steven Reynolds (Colorado St. University), Gerald
Akland (RTI International), Craig Hayes (North
Carolina Department of Agriculture and
Statistical Services) Sample Analysis Marcia
Nishioka (Battelle Columbus), Robin Helburn (RTI
International), and David Camann (Southwest
Research Institute) DISCLAIMER Although this
work was reviewed by EPA and approved for
publication, it may not necessarily reflect
official Agency policy.