Conference Call with Pyrethroid Working Group (PWG) on Proposed Voluntary Pyrethroid Use

Survey Design – Meeting Summary

Thursday, May 30, 2013; 10 – 11am

Participants

EPA:  Pesticide Reevaluation Division – Monica Wait, Molly Clayton, Dana Friedman, Tracy

Perry; Environmental Fate and Effects Division – Mah Shamim, Jose Melendez; Biological

and Economic Analysis Division – Jonathan Becker; Health Effects Division – Matt Crowley,

Kelly Lowe

PWG:  Dick Collier, Alex Porges, Jeff Giddings, Ann Orth, Kevin Henry, Genni Miller

Background

 On April 12, 2013, PWG provided EPA with information regarding their proposed

voluntary use/usage survey, “Survey of Residential Use of Pyrethroids in Geographically

Diverse Regions of the United States” (MRID 49116902).  PWG intends to use the

resulting survey data to inform the registration review process for pyrethroids, and they

requested EPA’s feedback on the draft survey.

 On May 23, 2013, EPA provided PWG with our preliminary comments and questions on

the survey. In general, EPA has some broad concerns regarding the survey design and

ability of the survey, as designed, to provide specific data and be of sufficient quality for

EPA to use quantitatively in the risk assessment process.

Discussion

 PWG clarified that the objective of the survey is to compare pyrethroid use patterns

across the US to those which were reported in a previously conducted California

pyrethroid use survey.  PWG expects that pyrethroid use in CA would represent a worst

case scenario, and they want to investigate use patterns for other regions of the US to

compare them to CA.  EPA noted that the proposed survey seems to be more broad in

nature than the previous CA survey and does not include the same level of detailed

questions.

 PWG clarified that the intent of the proposed survey is to inform the ecological risk

assessment for pyrethroids and it is not intended to provide information relevant to the

human health risk assessment, which will largely be provided by the ongoing REJV

survey.
 PWG discussed that they intend to use the information from the proposed use / usage

survey to parameterize their urban runoff modeling for other areas outside of CA using

the Storm Water Management Model (SWMM).  The model has been configured to

mimic a residential site (Aliso Viejo, CA), and validated against monitoring data.  PWG

believes that the site represents a conservative scenario.  EPA noted that OPP uses the

PRZM/EXAMS models for its ecological risk assessment modeling.

 PWG noted that, at least initially, the neighborhood and geographic parameters of their

model would still be based on CA data/neighborhood, although the pyrethroid usage

parameters from the proposed survey would be specific to other regions.  EPA noted

that generalizing neighborhood and geographical parameters (e.g. lot size, driveway

size, lawn area) from CA to other regions may be flawed.

 PWG clarified that the survey information sent to EPA on 5/12/13 was not the actual

survey instrument that would be used during the interviews.  What PWG provided to

EPA was a summary of the survey instrument which combined several questions that

are intended to stand alone.  This caused some confusion as EPA developed our

comments under the assumption that the submitted survey design was the actual

survey instrument.

 In general, EPA and PWG reviewed several of EPA’s questions and concerns.  PWG

provided feedback and additional information and noted that some of EPA’s comments

would be used to refine the proposed pyrethroid use survey design.

Conclusions / Next Steps

 PWG stated that they intend to provide written responses to EPA’s preliminary

questions and comments.

 PWG expects to conduct the proposed pyrethroid survey during the summer of 2013,

to have results by the end of the summer, and to include the survey data in their

pyrethroid modeling which they hope to complete by December 2013.

 EPA expressed concern about the timing and robustness of the proposed survey and

the potential impact on EPA’s ability to use the results quantitatively in risk

assessments.  EPA is willing to review an updated survey design and/or the actual

survey instrument, if desired by PWG and compatible with EPA staff workload timing.

 EPA and PWG have a meeting scheduled for June 27, 2013 to discuss PWG’s previously

submitted white paper on pyrethroid ecological risk assessment.