Appendix A

Public Agendas from Committee Meetings

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^*Invited meeting participants were asked to make presentations to the committee in response to the following questions:

Post-Vietnam Handling and Use of the C-123s

• What were the methods of cleaning, painting, etc., performed on the C-123s that had sprayed herbicides before they were provided to the Air Force Reserve? How and with what?

• While they were being used by the Air Force (AF) Reservists? Particularly for “Patches”? How frequently were the aircraft cleaned? How and with what?
• What was the usual duration of crew members being inside the C-123s (both in flight and on the ground such as training exercises)? Please include preparation time for a flight, flight time and unloading time. And, what would be a plausible range of time (in hours or parts of an hour) spent in/on the planes? On a single weekend? Over the summer weeks?
• Was any food consumed during a flight, and if so what type and how often?
• What type of activities (on the ground and in the air) were crew members involved in while using the C-123s? (e.g., activities that might result in contact with surfaces, generate dust, exposure to new areas, clean surfaces)—Please estimate the duration of each activity.
• How were the reservists assigned to the airplanes? (e.g., always flying the same planes? Or different assignments made each time? etc.)
• What protective clothing (e.g., gloves, shirts, pants) were worn by pilots, other flight crew, and maintenance personnel when in an aircraft? Did this change seasonally? What facilities were available for cleaning hands within the aircraft?

Collection and Analysis of Samples

• What would be the effect of environmental factors (e.g., sunlight, heat, etc.) on 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) degradation? Are there other factors that might affect degradation? What would be the extent of difference on residues on the planes’ interiors and exteriors?
• What is the nature of TCDD’s physicochemical properties? How would they influence human exposures from herbicide residues on the aircrafts’ interiors? How would they influence the content of samples obtained over an extended period of time? Should these physicochemical properties be considered when interpreting the sampling results?
• What environmental factors or activities in the C-123 could have affected the stability of TCDD in the interior of a plane?
• How might TCDD in the surface residues be transferred to dust? What conditions might promote or decrease that process?
• What solvents were used in gathering surface wipes in each period of sampling? Are there any implications for the comparability of the samples? • What do you think would constitute representative sample(s) for estimating the TCDD exposure of the C-123 Reservists, and why? What combination of available sampling data comes closest to this standard?
• Do you have any opinions or thoughts as to why the 1994 and 1995 samples from “Patches” are so different?

• Under what conditions were the air samples collected (plane on ground with or without door open; plane in flight)?

Modeling with Existing Data

• What is the plausible range of values that could be used as inputs for each of the parameters in the various models?
• The specific values quoted for Model 1 in Lurker’s abstract of 0.92 and 5.4 pg/kg-birthweight (BW)-day for the flight crew and maintainers differ from the results the committee obtained (3.0 for 60 kg and 2.5 for 70 kg BW) from equation 2 and using 42 days/year from Table 4 and 250 days/ year. Please go through the calculations for the Model 1 results given in the paper given that we were unable to reproduce it from the input parameters given in Table 4 using equation 2.
• When modeling ingestion, what would you consider the most appropriate estimate and the plausible range for:
  • – hand to mouth frequency and
  • – transfer of TCDD from hand to mouth (for eating food, such as a sandwich, on a flight)?
• How do the assumptions governing TCDD ingestion applied in Lurker et al. (2014) compare with those used in the National Research Council (1988) approach to establishing reentry criteria after polychlorinated biphenyl (PCB) transformer fires? What is the impact on resulting estimates?
• Please explain how the physicochemical properties of TCDD would, or would not, make the application of Model 3 by Lurker et al. (2014) appropriate.

Interpretations of Resulting Exposure Estimates

• What are your opinions of the applicability of various existing health guidelines for TCDD for the case of the AF Reservists who served on C-123s that had previously been used to spray herbicides in Vietnam?
• What existing guidelines would be most appropriate for application to this situation?