Title: AHETF Scenario Design and Field Study Protocol for Mixing and Loading of Pesticide Products in Water-Soluble Packaging
1AHETF Scenario Design and Field Study Protocol
for Mixing and Loading of Pesticide Products in
Water-Soluble Packaging
- Jeff Evans
- Kelly Sherman
- Office of Pesticide Programs
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2AHETF Status Recap
- June 2008 HSRB reviewed the closed-cab airblast
scenario - Fall 2008 AHETF conducted 2 closed-cab airblast
field studies - October 2008
- HSRB reviewed the remaining field study protocols
for the closed-cab airblast scenario - HSRB reviewed the scenario design document and
field study protocols for the open-cab airblast
scenario - Summer 2009 AHETF plans to conduct several
closed-cab and open-cab airblast field studies
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3Whats Familiar about this Proposal?
- No change to AHETF Governing Document or most
SOPs - Design objectives, sample size and rationale, and
cluster configuration are all similar to other
AHETF scenarios reviewed - Protocol procedures related to ethical conduct
are similar, but all issues raised by EPA and
HSRB have all been addressed
4Whats Different about this Proposal?
- Monitors Mixer-Loaders crop is unimportant
- Scenario covers mixing dry pesticides in
water-soluble packets (WSPs) with water, and
loading the solution into various types of
equipment for application as liquid sprays - Liquid sprays may be applied to virtually all
types of crops, using a wide range of application
equipment, in all areas of the U.S. - New Format for AHETF a single protocol covers
all five proposed field study sites - 12 new or updated SOPs
- One new surrogate acephate
5AHETF Scenario Design and Field Study Protocol
for Mixing and Loading of Pesticide Products in
Water-Soluble PackagingScience
AssessmentJeff EvansHealth Effects Division
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6Scenario Definition
- Mixing/Loading soluble or wettable powder
pesticides enclosed in water-soluble packets
(WSP) - Scenario supports assessing WSP mixing/loading
for many crops under 3 sub-scenarios - Mixing of WSPs directly into the tank used for
the pesticide application - Mixing of WSPs into a "pre-mix" tank at the same
concentration to be applied to the crop - Mixing of WSPs into a tank as a concentrated
solution/suspension that must be further diluted
and transferred to the final application tank
7EPA Position on Scenario Definition
- We agree with the AHETF plan to informally
diversify these general equipment types - Each of the three sub-scenarios must be monitored
at least once within each cluster - Diversity will be achievedrandomly or
purposivelyby assigning mixer/loaders to
Amount-active-ingredient-Handled (AaiH) strata
within each cluster - The proposal for 25 subjects in 5 clusters of 5
subjects each is appropriate for this scenario
8Regulatory Requirements for PPE
- Minimum Personal Protective Equipment (PPE)
permitted by the Worker Protection Standard for
acephate and carbaryl when engineering controls
are used isĀ chemical-resistant gloves - Other attire includes long sleeved shirt, long
pants, shoes, socks - In case of emergency (e.g., bag rupture) other
PPE coveralls, chemical-resistant footwear, and
respirators must be available
9Inner Dosimeter Example
10Water-Soluble Packets
Packets containing dry flowable product
11Packets may be placed directly into the sprayer
tank
12Packets may also be placed into a variety of
holding tanks, either fully diluted for use or as
a concentrated solution for later further
dilution and transfer to a spray tank
13Many kinds of tanks are used
14Tanks may be indoors or outdoors
15Portable mixing stations may also be set up
16To accompany a variety of application scenarios
17Proposed Surrogate Pesticides
- EPA accepts the AHETFs selection of acephate and
carbaryl as surrogates - They are widely used and available in water
soluble packets - They are used on a wide range of crops on farms
of many sizes and types such that all AaiH strata
can likely be filled in each cluster - They have reliable analytical methods, have been
successfully used as surrogates in other AHETF
studies, and are known to have the required
stability under field study conditions
18Margins of Exposure for Maximum AaiH
Surrogate Acephate Carbaryl
Maximum AaiH 720 2000
Dermal MOE 858 531
Inhalation MOE 113 160
Combined MOE 100 123
19Proposed AaiH Strata
- All exposure durations will be at least 4 hours
- Each subject will mix/load at least 3 tanks of
spray mixture - Five strata of AaiH in each cluster
- 5 to 17 pounds ai handled
- 18 to 55 pounds ai handled
- 56 to 182 pounds ai handled
- 183 to 603 pounds ai handled
- 604 to 2,000 pounds ai handled (limit use of
acephate to 700 pound AaiH)
20Proposed Clusters
Location Climate Crop Types
New York Cool Orchard/Trellis
Louisiana Hot/Humid Field Crops (cotton, soybeans)
Michigan Cool Orchard/Trellis Vegetables
California (southern) Hot/Dry Orchard/Trellis Vegetables
Washington (eastern) Hot/Dry Orchard
21Conclusions of Science Assessment
- The Field and Laboratory QA/QC aspects are robust
- The Scenario is well defined
- This protocol has addressed the technical aspects
of applicable exposure monitoring guidelines - Draft - EPA Series 875 Group A - Applicator
Monitoring Test Guidelines - OECD Applicator Guidelines
- Good Laboratory Practices (GLPs) (40CFR Part 160)
- Limit AaiH of acephate to 700 pounds
22AHETF Scenario Design and Field Study Protocol
for Mixing and Loading of Pesticide Products in
Water-Soluble PackagingEthics Assessment
- Kelly Sherman
- Human Research Ethics Reviewer
- Office of Pesticide Programs
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23Value to Society
- Exposure data for workers who mix and load
pesticides contained in water-soluble packets are
needed to support EPA risk assessments - Studies conducted under this protocol will
constitute the entire exposure data set for this
scenario in the Agricultural Handler Exposure
Database (AHED) - Knowledge likely to be gained will be used to
estimate dermal and inhalation exposure from use
of a wide range of agricultural pesticides
available in water-soluble packets
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24Recruiting and Consent
- Equitable subject selection
- Fully informed choice
- Fully voluntary choice
- Respect for subjects
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25Risks, Benefits, and Risk-Benefit Balance
- Risks have been fully identified and effectively
minimized - Residual risks to subjects will be low
- Risks to subjects are reasonable in light of
potential societal benefits
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26Independent Ethics Review
- The Independent Investigational Review Board
(IIRB) of Plantation FL - Reviewed and approved the protocol and informed
consent materials - Is independent of the sponsors and investigators
- Is registered with OHRP
- Is seeking accreditation from AAHRPP
- IIRBs Human Research Protection Program Plan
was included among the LNX-002 materials
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27EPA Review
- No deficiencies relative to 40 CFR 26, subparts K
and L, or to FIFRA 12(a)(2)(P) - All issues identified in previous EPA and HSRB
reviews have been satisfactorily addressed - 21/24 issues addressed in the Scenario Design and
Field Study Protocol (dated 1/16/09) - 3 remaining issues addressed in the AHETFs
Response to EPAs Science and Ethics Review
(dated 5/12/09)
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28Representativeness
- Concern Are study participants representative of
the target population of growers and commercial
applicators? - Past AHETF efforts to address concern were
unsuccessful - New AHETF Proposal
- Characterize eligible growers both those
willing and unwilling to participate - Ask experts with local knowledge to assess
characteristics of willing and unwilling growers
in terms of representativeness - EPA View AHETF proposal is effective and
ethically acceptable
29Presentation of Individual Exposure Data
- Concern Workers who learn that their exposure is
lower than average might become complacent or
adopt riskier behavior - AHETF proposal
- Letter conveying the importance of diligence in
the handling of pesticides, regardless of the
workers individual exposure levels - Graphics depicting exposure distribution across
body parts for the individual worker and the
group average - EPA brochure describing safe practices for
pesticide handlers - EPA View AHETF proposal is effective and
ethically acceptable
30Localization of Spanish Translations
- Concern Spanish translations should reflect
specific terminology and wording common to the
study locale - AHETF proposal
- Modify documents as appropriate to meet local
needs - Contact people in different regions of the
country who provide pesticide safety training to
Spanish-speaking agricultural workers - Ask reviewers to suggests changes in wording that
would improve understanding in their geographic
area - Ask reviewers to suggest translations for certain
agricultural terms - EPA View AHETF proposal is effective and
ethically acceptable
31Applicable Ethical Standards
- Proposal for third-party research involving
intentional exposure of human subjects to a
pesticide, with the intention of submitting the
resulting data to EPA under the pesticide laws - The primary ethical standards applicable to the
conduct of this research are 40 CFR 26, Subparts
K and L
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32Conclusions of Ethics Assessment
- Protocol meets the applicable requirements of 40
CFR part 26, subparts K and L
33Charge Questions
- If proposed field study protocol AHE120 is
revised as suggested in EPAs reviews and if the
research is performed as described - 1. Is the research likely to generate
scientifically reliable data, useful for
assessing the exposure of handlers who mix and
load soluble or wettable powder pesticides in
water-soluble packaging? - 2. Is the research likely to meet the applicable
requirements of 40 CFR part 26, subparts K and
L?
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