# Appendix 4

Studies Excluded From the Department of Pesticide Regulation’s

Evaluation of Fumigant Volatile Organic Compound Emissions

A-64FumigantReferenceCommentGan, J., S.R. Yates, D. Wang, and W.F. Spenser. 1996. Effect ofsoil factors on methyl bromide volatilization after soilapplication. Environ. Sci. Technol. Vol 30:1629-1636.Soil column study. It has not been reliably demonstrated that soil columnresults reflect field scale resultsGan, J., S.R. Yates, W.F. Spenser, M.V. Yates, and W.A. Jury.1997. Laboratory-scale measurements and simulations of effectof application methods on soil methyl bromide emissions. J.Environ. Qual. Vol 26:310-317.Soil column study. It has not been reliably demonstrated that soil columnresults reflect field scale results.Majewski, M.S., M.M. McChesney, J.E. Woodrow, H.H.Prueger, and J.N. Seiber. 1995. Aerodynamic measurements ofmethyl bromide volatilization from tarped and nontarped fields.J. Environ. Qual. Vol 24:742-752.Results from these applications arealready included in the DPR MeBrdatabase as DPR studies.Yagi, K., J. Williams, N.-Y. Wang, R.J. Cicerone. 1995.Atmospheric methyl bromide (CH3Br) from agricultural soilfumigations. Science Vol 267:19791981.This study used chambers to measure flux. Flux results from thisexperiment differ significantly from a previous study by the same authorsusing the same application method (34% mass loss vs. 89% mass loss).Source of the difference was not adequately established and may simplybe due to the large variation observed when measuring flux by thechamber method.Yates, S.R., J. Gan, F.F. Ernst, A. Mutzinger, and M.V. Yates.1996. Methyl bromide emissions from a covered field: I.Experimental conditions and degradation in soil. J. Environ.Qual. Vol 25:184-192.Although air concentrations were measured on a central mast, no fluxestimates were included in the paper.The second paper (below) presentsthe flux estimates. In this paper, total mass loss was estimated only by soilbromine measurements. DPR has not used soil bromine measurements toestimate flux and mass loss.MethylBromideYates, S.R., F.F. Ernst, J. Gan, F. Gao, and M.V. Yates. 1996.Methyl bromide emissions from a covered field: I.IVolatilization. J. Environ. Qual. Vol 25:192-202.The air mast sampling timeline is not clearly shown in either of the papersin this set. The text of part I states that the application duration was 6.5hrs and that the application was interrupted to install the samplingequipment on the field. This seems toindicate that 1⁄2 of the applicationwas not sampled. The authors state inthe conclusions that large levels ofemissions result when MeBr is applied at shallow depth and the soilcovered with relatively permeable polyethylene tarp. Thus, due to thedelay in beginning sampling, the flux estimates may be biased low. Evenif these results were included, theloss estimate would not be differentfrom that obtained using the DPR data base exclusively.A-65Yates, S.R., D. Wang, F.F. Ernst, and J. Gan. 1997. Methylbromide emissions from agricultural fields: Bare-soil, deepinjection. Environ. Sci. Tech. Vol 31:1136-1143.No air samples for direct flux methods were taken during the 4 hourapplication. The authors note that the soil bromine measurements estimatea 21% mass loss while the direct flux methods estimate mass loss between2% and 5%. The authors speculate that the difference in mass loss wasdue to emissions during the application. The authors list 21% as the massloss in a subsequent journal article (phytopathology vol 92(12):1344-1348)indicating that they have placed more weight on the soil bromine estimate.In addition, the 68cm injection depth is 8cm deeper than usual practice of60cm.Yates, S.R., J. Gan, F.F. Ernst,D. Wang, and M.V. Yates. 1996.Emissions of methyl bromide from agricultural fields: Rateestimates and methods of reduction. In: J.N. Seiber, J.A.Knuteson, J.E. Woodrow, N.L. Wolfe, M.V. Yates, and S.R.Yates (Eds). Fumigants: Environmental fate, exposure, andanalysis. ACS Symposium Series 652. American ChemicalSociety, Washington, DC. pp 116-134.This book chapter summarizes result presented in other papers. No newdata is presented.A-661,3-DGao, S. and T.J. Trout. 2006.Using surface water application toreduce 1,3-dichlorpropene emissions from soil fumigation. J.Environ. Qual. Vol 35:1040-1048.This paper reports results from soil column experiments using only 1,3-D.The treatments:A. Dry soil/no tarp/no waterB. Initial water before fumigant injection/no tarpC. Treatment B + more water applied to soil surface at 12 hrs postinjectionD. Treatment C + more water applied to soil surface at 24 hrs postinjectionE. Dry soil covered with HDPEF. Treatment B covered with HDPEG. Dry soil covered with VIFFactors that limit the use of these results in the VOC program:1) The dry soil applications do not follow Telone label instructions andthus, do not reflect practices required by applicators in the field.2) Treatments C and D required that the soil column be opened in order forthe additional water to be applied tothe soil surface. The authors adjustfor the speculated effect of the disturbance of the equilibrium in the soilcolumn. However, there was no control column that was opened with nowater applied. Therefore, it is impossible to assign the response observedin the emissions to the water rather than the disturbance of the soil columnheadspace and equilibrium (or some interaction between the two). Theauthors argue that after the first sample following the opening of the soilcolumn following samples “...should not have been affected...” however,nothing is presented to support that assertion. The lack of a control forthis procedure likely invalidates the results of those treatments.A-67Gao, S. and T.J. Trout.2007. Surface seals reduce 1.3-dichloropropene and chloropicrinemissions in field tests. J.Environ. Qual. Vol 36:110-119.Treatmentsi) control – dry soilii) dry soil covered with HDPEiii) dry soil covered with VIFiv) Initial water before fumigant injection/covered with HDPEv) Dry soil injection followed by water application/no tarpvi) Treatment v + additional intermittent water at 8, 22, 28, 32,and 48hrFactors that limit the use of these results in the VOC program:1) The dry soil applications (i, ii, and iii) do not follow Telone labelinstructions and thus, do not reflect practices required by applicators in thefield.2) The intermittent water treatment (vi) pattern is not a reasonableprocedure for applicators to follow. There is no way to reliably adjust theexperimental results to reflect a more reasonable intermittent wateringpattern.3) Plots were different sizes. The water treatment plots were 9m x 9m.The tarp treatments were 9m x 3m.4) The plots are separated by 3m buffers. This is very close. It is possiblethat the water applications to the neighboring plots changed the fluxdynamics on the dry plots due to local changes in humidity.5) Emission measurements were taken using chambers. The authorsspeculate about the reliability of chamber results, particularly for the drysoil treatments (giving one more reason to not use the dry soil results).They state: “We highly suspect that the passive chamber method mightunderestimate fumigant emissions froma bare and dry soil surface becausea perfect seal between the chamberand the soil was difficult to formduring the 30 min capture time.” This section of the text that casts doubton the reliability of the results.6) The 30 min capture time is also anissue. These are snap-shots in timeand how well they characterize loss over longer periods is not discussed.7) No emission measurements were taken at night. The authors speculatethat the control treatmentpeak flux occurred at night because for both 1,3-D and chloropicrin the total control mass loss is less than HDPE loss. Theyalso speculate that the peak flux forthe HDPE treatmentoccurred early inthe morning when no measurements were taken. However, they do notapply the same speculation to any ofthe other treatments. Due to the studydesign, the flux profiles arenot adequately characterized.A-68van Wesenbeeck, I.J., C.K. Robb and D.A. Lindsay. 1998. Fieldvolatility of 1,3-dichloropropene from an untarped buried dripapplication in the Rio Grande Valley of Texas Amended Report.Study ID ENV97106 Dow AgroSciences LLC, Indiana.This study was not used for the following reasons: 1) puddling ondownwind portion of field led to inconsistency between concentrationsand fluxes and created uncertaintyin the flux (2) study was untarped(current label requires tarping)Gan, J., S.R. Yates, F.F. Ernst, and W.A. Jury. 2000.Degradation and volatilization offumigant chloropicrin aftersoil treatment. J. Environ. Qual. Vol 29:1391-1397.Soil column study. Has not been reliably demonstrated that soil columnresults reflect field scale resultsGao, S. and T.J. Trout.2007. Surface seals reduce 1.3-dichloropropene and chloropicrinemissions in field tests. J.Environ. Qual. Vol 36:110-119.See comments for this article in the 1,3-D section above.Gillis, M. and G.S. Smith. 2002. Chloropicrin emissions andoffsite drift from tarped and non-tarped fields treated by a dripirrigation application method. Study TC350. Unpublishedreport submitted to CDPR. DPR Registration Volume 199-0114.This study was not used because the quality assurance/quality control datasubmitted in support of the study results was not of acceptable quality.Lee, H., K.V. Natta, and M. Gillis. 1994.. Chloropicrin workerexposure, flux, and offsite monitoring and dispersions modelingfor tarped broadcast application – pilot study. StudyTC246/BR707. Unpublished report submitted to CDPR. DPRRegistration Volume 199-0079.This study was not used for the following reasons: 1) No acceptablequality assurance/quality control data wasinclude in the report, 2) no tableshowing the flux calculations was included in the report, 3) dispersionmodeling underestimated the observed concentrations indicating that theflux estimates were low.Wang, D., J. Juzwik, and S. Fraedrich, K. Spokas, Y. Zhang,and W.C. Koskinen. 2005. Atmospheric emissions of methylIsothiocyanate and chloropicrin following soil fumigation andsurface containment treatment in bare-root forest nurseries. Can.J. For. Res. Vol 35:1202-1221.This study was not included becauseflux was estimated using passivechambers. Due to significant technicalissues with chamber sampling DPRhas elected to omit flux estimates obtained using chambers.ChloropicrinZhang, Y. and D. Wang. 2007. Emission, distribution, andleaching of methyl Isothiocyanate and chloropicrin underdifferent surface containments. Chemosphere 68:445-454.Soil column study. It has not been reliably demonstrated that soil columnresults reflect field scale results.A-69Zhang, Y. and D. Wang. 2007. Emission, distribution, andleaching of methyl Isothiocyanate and chloropicrin underdifferent surface containments. Chemosphere 68:445-454.Soil column study. It has not been reliably demonstrated that soil columnresults reflect field scale results.Sullivan, D.A., M.T. Holdsworth, H. Ajwa, S. Nelson, D.Dickson. 2003. Draft Report.Citra, Florida studies ofincorporation and drip irrigation with tarping. SubmittedSeptember 24, 2004 on behalf of the Metam Sodium TaskForce. DPR Registration Volume number 50150-0159.This study was not included for the following reasons: 1) the applicationand mitigation methods are not adequately described, 2) there is no qualityassurance/quality control data included, 3) only a summary of estimationof flux is provided so no review is possible, 4) even if the information tofully review the flux estimates was submitted, the summary indicates thatthe flux back-calculation used log-transformed data which is notacceptable.Sullivan, D.A. and M.T. Holdsworth. 2004 Study of Roozenshank injection rig at Washington Bulb Co. site, Mount Vernon,Washington. Submitted September 24, 2004 on behalf of theMetam Sodium Task Force. DPR Registration Volume number50150-0158.This study was not included for the following reasons: 1) the applicationand mitigation methods are not adequately described, 2) there is no qualityassurance/quality control data included, 3) only a summary of estimationof flux is provided so no review is possible, 4) even if the information tofully review the flux estimates was submitted, the summary indicates thatthe flux back-calculation used log-transformed data which is notacceptable.Sullivan, D.A. and M.T. Holdsworth. 2001. Orange County dripapplication study modeling results prepared for the MetamSodium Task Force. Sullivan Consulting, Inc. 1900 ElkinStreet, Suite 249, Alexandria, VA 22308. Report datedDecember 18, 2001.This study was not included becauseit is a pilot study that employedminimal air concentration sampling not sufficient to reliably estimate flux.In addition, at the time of application the soil was not within the labeledmoisture range. There is no quality assurance/quality control datasubmitted.Sullivan, D.A. and M.T. Holdsworth. 2001. Lancaster pilotstudy of intermittent sealing for a sprinkler irrigation application. Prepared for the Metam Sodium Task Force SullivanConsulting, Inc. 1900 Elkin Street, Suite 249, Alexandria, VA22308. Report dated December 18, 2001.This study was not included becauseit is a pilot study that employedminimal air concentration sampling not sufficient to reliably estimate flux.The application plots were very narrow rectangles that could significantlyaffect the results. There is no quality assurance/quality control datasubmitted.Sullivan, D.A. and M.T. Holdsworth. 2001. Santa BarbaraCounty pilot study of intermittent sealing for a shank injectionapplication. Prepared for the Metam Sodium Task ForceSullivan Consulting, Inc. 1900 Elkin Street, Suite 249,Alexandria, VA 22308. Report dated December 18, 2001.This study was not included becauseit is a pilot study that employedminimal air concentration sampling not sufficient to reliably estimate flux.The application plots were very narrow rectangles that could significantlyaffect the results. There is no quality assurance/quality control datasubmitted.Sullivan, D.A. and M.T. Holdsworth. 2001. Panama Lane pilotstudy of intermittent sealing for a chemigation application .Prepared for the Metam Sodium Task Force. SullivanConsulting, Inc. 1900 Elkin Street, Suite 249, Alexandria, VA22308. Report dated December 18, 2001.This study was not included becauseit is a pilot study that employedminimal air concentration sampling not sufficient to reliably estimate flux.The application plots were very narrow rectangles that could significantlyaffect the results.Edison Road 2005. Early start/sunset sealThis study has not been submitted to DPRUSDA Salinas 2004 Shank/tarpThis study has not been submitted to DPRMetam SodiumUSDA Salinas 2004 Drip/tarpThis study has not been submitted to DPRA-70Brawley 2004 FloodThis study has not been submitted to DPRUSDA 2002 Bakersfield shankThis study has not been submitted to DPRUSDA 2002 Bakersfield chemigationThis study has not been submitted to DPRFirebaugh 1992 chemigationThis study has not been submitted to DPR.ARB. 1993. Ambient air monitoring in Contra Costa Countyduring March 1993 after an application of Metam Sodium to aField. Test Report No. C92-070A. July 14, 1993.http://www.cdpr.ca.gov/docs/emon/pubs/tac/tacpdfs/metamsod.pdfThis study was not designed to estimate flux. Air sampling is insufficientand the meteorological data is not available.ARB. 1993. Ambient air monitoring for MITC in Kern Countyduring summer 1993. Test Report No. C92-070. April 27, 1994.http://www.cdpr.ca.gov/docs/emon/pubs/tac/tacpdfs/mitckern.pdfThis study was not designed to estimate flux. Air sampling is insufficientand the meteorological data is not available.Wang, D., J. Juzwik, and S. Fraedrich, K. Spokas, Y. Zhang,and W.C. Koskinen. 2005. Atmospheric emissions of methylIsothiocyanate and chloropicrin following soil fumigation andsurface containment treatment in bare-root forest nurseries. Can.J. For. Res. Vol 35:1202-1221.This study was not included becauseflux was estimated using passivechambers. Due to significant technicalissues with chamber sampling DPRhas elected to omit flux estimates obtained using chambers.Zhang, Y. and D. Wang. 2007. Emission, distribution, andleaching of methyl Isothiocyanate and chloropicrin underdifferent surface containments. Chemosphere 68:445-454.Soil column study. It has not been reliably demonstrated that soil columnresults reflect field scale results.A-71