AHETF Scenario Design and Field Study Protocol for Mixing and Loading of Pesticide Products in Water-Soluble Packaging

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AHETF 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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AHETF 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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Whats 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

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Whats 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

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AHETF 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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Scenario 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

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EPA 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

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Regulatory Requirements for PPE

• Minimum Personal Protective Equipment (PPE)
  permitted by the Worker Protection Standard for
  acephate and carbaryl when engineering controls
  are used is 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

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Inner Dosimeter Example
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Water-Soluble Packets
Packets containing dry flowable product
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Packets may be placed directly into the sprayer
tank
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Packets 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
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Many kinds of tanks are used
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Tanks may be indoors or outdoors
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Portable mixing stations may also be set up
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To accompany a variety of application scenarios
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Proposed 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

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Margins of Exposure for Maximum AaiH
Surrogate Acephate Carbaryl
Maximum AaiH 720 2000
Dermal MOE 858 531
Inhalation MOE 113 160
Combined MOE 100 123
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Proposed 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)

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Proposed 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
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Conclusions 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

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AHETF 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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Value 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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Recruiting and Consent

• Equitable subject selection
• Fully informed choice
• Fully voluntary choice
• Respect for subjects

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Risks, 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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Independent 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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EPA 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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Representativeness

• 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

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Presentation 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

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Localization 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

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Applicable 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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Conclusions of Ethics Assessment

• Protocol meets the applicable requirements of 40
  CFR part 26, subparts K and L

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Charge 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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