Page 1 of 43 UNITED STATES ENVIRONMENTAL PROTECTION AGENCY WASHINGTON, D. C. 20460 OFFICE OF PREVENTION, PESTICIDES AND TOXIC SUBSTANCES Date: March 28, 2006 Memorandum:

SUBJECT: Secondary Review of " Biomonitoring of Workers Hand Thinning Peaches Treated with Phosmet Insecticide"; MRID 446823 01. PC Code 059201. DP Barcode D 296574.

FROM: Matthew Lloyd, Industrial Hygienist Reregistration Branch I Health Effects Division ( 7509C)

THROUGH: Whang Phang, Branch Senior Scientist Reregistration Branch I Health Effects Division ( 7509C)

TO: Diane Isbell Reregistration Review Branch 2 Special Review and Reregistration Division ( 7508C)

Attached is a review of the Biomonitoring of Workers Hand Thinning Peaches Treated with Phosmet Insecticide ( MRID 466823 01 & 46682302) study submitted by Gowan Company in support of the re registration of Phosmet. This review was completed by Versar, Inc. under the supervision of HED. It has undergone secondary review and reflects current Agency policies. Page 2 of 43 Executive Summary:

This study was designed to examine postapplication exposure to workers hand thinning peach trees following airblast application of Phosmet insecticide. The study measured the change in plasma and red blood cell cholinesterase activity and to characterized urinary excretion of an absorbed dose of Phosmet. Urine was analyzed for the urinary metabolites of Phosmet ( N( methylsulfinyl) methyl phthalamic acid and N ( methylsulfonyl) methylphthalamic acid), the sulfinyl and sulfonyl metabolites ( assayed as oxidized sulfonyl). Potential Phosmet equivalents were calculated using a molecular weight conversion factor applied to the metabolite residue concentration. Dislodgeable foliar residues ( DFRs) of Phosmet and Phosmet oxon were also measured for one day pre second application and for the two days following the second application.

A 70% active ingredient ( ai) wettable powder formulation of Phosmet was applied by airblast sprayer at the maximum label rate of 3 lb ai/ acre to mature peach trees near Morven, Georgia in the spring of 2005. This application was made 14 days following the first seasonal application of Phosmet to that peach orchard. A crew of 16 workers ( 14 male and 2 female) re entered the field two days after the second application, in order to hand thin the trees. Blood and 24 hour urine samples were collected from the workers on four pre exposure days, four post exposure days, and on the day of exposure.

The 24 hour urine collections were assayed for creatine and sulfonyl concentration. To account for incomplete sample collection, the Study Report compared measured creatinine to expected creatinine for each individual at each sampling event. Based on this estimate of expected creatinine, an adjustment factor was applied to the sulfonyl concentration in each urine collection. The Study Author did not factor any pharmacokinetic data into the estimation of phosmet equivalent dose. One factor typically considered in the estimate of dose is the percentage of active ingredient converted to urinary metabolite and subsequently excreted in the urine. Another factor to be considered is the percentage of metabolite expected to be excreted during the sampling time period. The Study Report protocol states that the sulfinyl and sulfonyl metabolites of phosmet account for approximately 50 60% of the administered radioactivity in urine in a rat oral metabolism study. HED made corrections for the percentage of active ingredient converted to urinary metabolite and excreted in urine ( 95%) and a correction ( 55%) to account for the percentage of administered radioactivity in urine in a rat oral metabolism study ( MRID 404253 01) in their estimate of dose.

Both plasma and red blood cell cholinesterase activity was monitored throughout the conduct of the study, as well as on several pre exposure days. The Study Author reported no remarkable findings and no exposure related depression of either plasma or red blood cell cholinesterase activity for the designated exposure day.

Dislodgeable foliar residue ( DFR) was measured on the day before the second application, the day of the second application ( 2 days prior to reentry activity) and for the following 5 days ( i. e., 7 monitored days). The Study Author concluded that the continuing hard rain at the end of the exposure day had affected the dissipation kinetics Page 3 of 43 and reported that a meaningful dissipation curve could not be developed. The residues on days one and two after the phosmet application demonstrate residue levels consistent with previous Phosmet DFR studies, though after the rain event the phosmet residues drop off significantly. The Phosmet oxon was also measured in the DFR and was found to be a tiny fraction of the parent.

There were a number of issues that introduced uncertainty into the study, including the following:

  Stormy weather changed the intended activity day from day 3 postapplication to day 2 postapplication With a forecast predicting rain, the study authors moved up the worker postapplication activity day from day 3 postapplication to day 2 postapplication. The rain began to fall in the afternoon of day 2 postapplication while the workers were still conducting thinning.

  Shortened work day due to rain event On the reentry day, an afternoon thunderstorm forced the subjects to take cover for half an hour. They returned to work, although the rain intensity steadily increased and the work day was called off. Total working time was roughly 6 hours before the rain and half an hour in the rain for a 6.5 hour workday.

  DFR analysis compromised by the rain event The Study Author concluded that the continuing hard rain at the end of the exposure day had affected the dissipation kinetics and reported that a meaningful dissipation curve could not be developed. The residues declined from 4.06 ug/ cm2 on day 2 ( the day the rain started) to 0.99 ug/ cm2 on day 4 ( the day the rain ended). The Study Report did not detail what time of the day the DFR samples were collected, further complicating interpretation of the DFR results.

  Poor participant compliance with urine collection The Study Report details compliance issues with regard to urine sample collection procedures. Many of the 24 hour urine collections demonstrate total volumes substantially below what is expected for normal, healthy adults. The volume of urine produced by a normal adult over a 24 hour period typically ranges between 800 and 1800 mL ( Tietz, 1970). Sample volumes obtained from the 16 workers against this standard demonstrate that 28 of 123 urine collections were below what normally would be expected. The study authors cited an instance of a field observer witnessing a study participant urinating on the ground, instead of in the sample collection bottles. Page 4 of 43   Unknown effect of rain on thinning activity day The effect of the rain event on the phosmet exposure estimate is unknown. The rainfall could have washed the transferable residue from the leaves, and/ or washed residue from the workers' skin and clothing. It was also possible that the rain would solubilize the DFRs making them more readily available for transfer, or the water mass could have pushed residues through the clothing to skin increasing dermal exposure, or that the damp clothing could hydrate the skin, possibly enhancing dermal absorption.

  Inconsistent worker apparel The study authors requested workers to have socks, shoes, long pants and a long sleeve shirt. No one was turned away from wearing more clothing than initially requested. The day warmed up quickly and a number of workers shed some clothing as the temperature increased. They then added it back on at some point during the rain event. Exposure is difficult to characterize accurately in these circumstances. A few of the workers wore jackets for part of the workday, some of the workers wore gloves, some wore hats, some workers wore short sleeved shirts and others wore long sleeved shirts. Seven of sixteen had more clothing than study authors requested for at least 2 hours. That includes clothing items like caps, hats, gloves, and jackets.

  Analytical lab utilized for cholinesterase activity does not have data to support whether storage length of samples ( 1 month) frozen blood samples would affect storage stability The study report does not mention storage temperatures for the blood samples. There is a possibility that the interaction of the phosmet and the enyzme may be altered during storage. Page 5 of 43 DFR vs. time for Georgia Biomonitoring Study 0 1 2 3 4 5 6 7 DAY AFTER TREATMENT 0 1 2 3 4 5 DCNA Residue UG/

CM2 R square = 0.924 # pts = 6 y = 5.77 +  0.96x PEACH DFR DATA FOR THE GEORGIA TEST SITE Page 6 of 43 References:

Tietz, Norbert W. ed. ( 1970). Fundamentals of Clinical Chemistry, Philadelphia, PA: W. B. Saunders Company. ISBN 0 7216 8865 9. Page 7 of 43 Reviewer: Teri Schaeffer/ Traci Brody/ Susan Anderson Date: March 10, 2006 STUDY TYPE: Post application biological monitoring study TEST MATERIAL: Phosmet SYNONYMS: Imidan ® O, O dimethyl S phthalimidomethyl phosphorodithioate ( IUPAC)

CITATION: Study Author: Douglas G. Baugher, Ph. D. Title: Biomonitoring of Workers Hand thinning Peaches Treated with Phosmet Insecticide. Report Date: October 31, 2005 Analytical Laboratories: PTRL West, Inc. 625 B Alfred Nobel Drive Hercules, CA 94547 Identifying Codes: MRID: 46682301 Report No.: 0512 Study Number: EXP 49404 SPONSOR: Gowan Company 370 South Main Street Yuma, AZ 85364 EXECUTIVE SUMMARY:

This study was designed to examine postapplication exposure to 16 workers hand thinning peach trees following airblast application of phosmet insecticide. The study proposed to measure the change in plasma and red blood cell cholinesterase activity and to characterize urinary excretion of an absorbed dose of phosmet following one day of hand thinning peach trees at the reentry interval ( REI) of two days postapplication. Urine was analyzed for the urinary metabolites of phosmet ( N( methylsulfinyl) methyl phthalamic acid, and N( methylsulfonyl) methylphthalamic acid), the sulfinyl ( SI) and sulfonyl ( SO) metabolites ( assayed as oxidized sulfonyl). Potential phosmet equivalents were calculated using a molecular weight conversion factor applied to the metabolite residue concentration. A small sampling of dislodgeable foliar residues ( DFRs) of phosmet and phosmet oxon were also presented.

A 70% active ingredient ( ai) wettable powder formulation of phosmet was applied by airblast sprayer at a use rate of 3 lb ai/ acre to mature peach trees near Morven, Georgia in the spring of 2005. The application rate was verified by application pass times rather than tank mix analysis. The application was made 14 days following a first seasonal application event. A crew of 16 workers ( male and female) re entered the field two days after the second application, in order to hand thin the trees. Blood and 24 hour urine samples were collected from the workers on four pre exposure days, four post exposure days, and on the day of exposure.

The Study Authors estimated phosmet equivalent dose by measurement of the urinary sulfonyl ( SO) and sulfinyl ( SI) metabolites of phosmet in 24 hour urine samples collected for five consecutive days beginning on the morning of postapplication reentry. Over half of the pre exposure samples showed no detectable level of SO residue in the urine. Total estimated phosmet equivalents ranged from 1,031 µ g/ day to 9,488 µ g/ day. These reported phosmet equivalents do not, however, take into consideration the pharmacokinetics of phosmet metabolism. The highest daily concentrations was generally found on the first exposure day ( ED 0), although four of the sixteen workers Page 8 of 43 demonstrated the highest urine levels on the second exposure day ( ED + 1). Levels steadily decreased during the monitoring period; however, the levels did not reduce to pre exposure levels by the end of the sample collection period.

Both plasma and red blood cell cholinesterase activity was monitored throughout the conduct of the study, as well as on several pre exposure days. The Study Author reported no remarkable findings and no exposure related depression of either plasma or red blood cell cholinesterase activity.

Dislodgeable foliar residue ( DFR) was examined on the day before the second application, the day of the second application ( 2 days prior to reentry activity) and for the following 5 days ( i. e., 7 monitored days). The Study Author concluded that the continuing hard rain at the end of the exposure day had affected the dissipation kinetics and reported that a meaningful dissipation curve could not be developed. The residues on the day of second application and the following day demonstrated residues comparable to previous phosmet DFR studies. The phosmet DFR on days 1 and 2 postapplication averaged 5.9 ug/ cm2 and 5.0 ug/ cm2, respectively. Phosmet oxon DFR on days 1 and 2 postapplication averaged 0.012 ug/ cm2 and 0.010 ug/ cm2, respectively.

Major issues of concern in evaluation of the study include:

  Other than a molecular weight factor to account for the difference in molecular weight between the urinary metabolite sulfonyl, and the active ingredient phosmet, the Study Author did not factor any pharmacokinetic data into the estimation of phosmet equivalent dose. One factor typically considered in the estimate of dose is the percentage of active ingredient converted to urinary metabolite and subsequently excreted in the urine. Another factor to be considered is the percentage of metabolite expected to be excreted during the sampling time period. The Study Report protocol states that the sulfinyl and sulfonyl metabolites of phosmet account for approximately 50 60% of the administered radioactivity in urine in a rat oral metabolism study. The Authors did not take this into consideration in their estimate of dose.

  Many of the 24 hour urine collections demonstrate total volumes substantially below what is expected for normal, healthy adults. The volume of urine produced by a normal adult over a 24 hour period typically ranges between 800 and 1800 mL ( Tietz, 1970). Sample volumes obtained from the 16 workers against this standard demonstrate that 28 of 123 urine collections were below what normally would be expected.

  The Study Authors attempted to correct for incomplete urine collection. They adjusted sulfonyl concentration in the urine samples using a technique which compared measured creatinine to expected creatinine for each individual at each sampling event ( Mage et al., 2004). Based on this estimate of expected creatinine, an adjustment factor was applied to the sulfonyl concentration in each urine collection. Use of this correction strategy resulted in adjustment factors ranging from 0.64 to 4.38. Use of factors of this magnitude indicates that in some instances, urine volume was as low as 25% of the expected volume.

  The study Authors also applied the adjustment factor to those samples where the actual creatinine level was higher than the expected creatinine level ( e. g., adjustment factor < 1.0). This had the effect of reducing the sulfonyl/ sulfinyl that was actually excreted by those individuals.

  The DFR analysis was most likely compromised by an exposure day rainfall event. The Study Report states that the " continued hard rain at the end of the exposure day had affected the dissipation kinetics and that a meaningful dissipation curve could not be developed." The study authors report that residue levels on the first and second day after the second application ( approximately 6 and 5 ug/ cm2, respectively) were consistent with expected DFR values. When comparing the DFR results with previously conducted phosmet dissipation regression curves, it appears that residues levels determined after the rain event demonstrate significantly lower levels than those expected.

  In the afternoon of the reentry day, postapplication activities were cut short due to heavy rain. The affect of this event on the phosmet exposure estimate is unknown. It is possible; however, that meaningful exposure Page 9 of 43 was affected. The rainfall could have washed the transferable residue from the leaves, and/ or washed residue from the workers' skin and clothing. Or it is possible that the rain would solubilize the DFRs making them more readily available for transfer, or the water mass could have pushed residues through the clothing to skin increasing dermal exposure, or the damp clothing could hydrate the skin, possibly enhancing dermal absorption.

  Urinary field fortification levels were inconsistent, with seven samples, or 25%, demonstrating recovery values less than 50%. The Study Author deleted these values from the calculation of average recovery, reporting that the values must have been misfortified. If these fortification values were included in the calculations, overall recovery would be 84%, necessitating the use of a correction factor.

  The clothing worn by the workers was inconsistent. It is difficult to accurately characterize exposure in these circumstances. Table 1 outlines the clothing worn by the individual workers. A few of the workers wore jackets for part of the workday, some of the workers wore gloves, some wore hats, some workers wore shortsleeved shirts and others wore long sleeved shirts.

  Several of the urine samples demonstrate incomplete oxidation of sulfinyl metabolite to the quantified metabolite, sulfonyl. The phosmet equivalent levels are based on measurement of sulfonyl only. The Study Authors did not adjust the estimate of phosmet concentration to account for this.

  EPA Reg No. 10163 169 specifies a maximum use rate of 4.25 lbs. ai/ A. The test substance was applied to the peach trees at a rate of 3 lbs. ai/ A.

  Postapplication activities were cut short ( i. e., the workers worked 6.5 hours on the day of exposure) due to the rainfall.

  Creatinine levels were determined; however, it was not reported if the specific gravity of the urine was analyzed.

  It is not well established that washed red cells can be frozen for a period of approximately one month and then assayed for RChe activity, as was the case in this Study. The laboratory utilized by the Study Author reports that their RChe method was validated using fresh specimens ( within 48 hours of collection) for estimation of RChe activity. The analytical lab utilized for cholinesterase testing does not have data to support whether or not frozen storage would affect stability.

  This study was conducted at only one test site, a peach orchard in Morven, Georgia. Therefore, DFR data was not collected from at least three geographically distinct locations for each formulation and crop type as specified in the guidelines. Page 10 of 43 COMPLIANCE: Signed and dated GLP, Data Confidentiality statements, and Quality Assurance statements were provided in the Study Report. The Study Report states that it meets FIFRA Good Laboratory Practices 40 CFR part 160 with the following exceptions: ( 1) the clinical facilities did not operate under the GLP, but were licensed and accredited; ( 2) no data evaluations, interpretations, or reports were generated by the labs; ( 3) tank mix samples were not collected during the application of the test product; ( 4) one set of the field fortified urine samples was placed into a freezer rather than into a cooler; ( 5) LabCorp was not identified in the study protocol as the facility used to assay blood samples; and ( 6) the Study Director selected the samples for analysis and inclusion in reporting based on relevance to the study objectives without protocol amendment. The statement noted that none of these exceptions negatively impacted the integrity of the study.

GUIDELINE OR PROTOCOL FOLLOWED: The Protocol was approved by the Western Institutional Review Board ( WIRB) and provided in the Study Report. The Study Report states that the exposure data requirements were from U. S. EPA OPPTS Harmonized Test Guidelines, Series 875 Occupational and Residential Exposure, Group B 875.2600, Biological Monitoring. The DFR data requirements were from U. S. EPA OPPTS Harmonized Test Guidelines, Series 875, Part B: Dislodgeable Foliar Residue Dissipation: Agricultural, Guideline 875.2100.

I. MATERIALS AND METHODS A. MATERIALS 1. Test Material:

Formulation: Imidan ® 70 W  water soluble packets containing 70% phosmet as the active ingredient. Lot/ Batch # formulation: Imidan ® : 316 129A/ 30AK4163 Phosmet oxon: 1232W 001B Sulfinyl urinary metabolite: 13449 5 Sulfonyl urinary metabolite: 13449 8 Purity: Imidan ® : The purity of the batch was verified at 98% with an expiration date of February, 2007. Phosmet oxon: The purity of the batch was verified at 99.7% with an expiration date of November 3, 2006. Sulfinyl urinary metabolite: The purity of the batch was verified at 93.86% with an expiration date of June 22, 2006. Sulfonyl urinary metabolite: The purity of the batch was verified at 97.01% with an expiration date of June 22, 2006. CAS #( s): Phosmet: 732 11 6 Other Relevant Information: Imidan ® 70 W  EPA Reg. No. 10163 169 2. Relevance of Test Material to Proposed Formulation( s): A label was not provided with the Study Report; however, Versar was able to obtain a label from the OPP Pesticide Products Database using the EPA registration number. The wettable powder formulation sent to the field sites was labeled as Imidan   70 W, which is the same product name that appears on the label.

3. Packaging: The product was packaged in water soluble bags in 40 lb cardboard cartons.

B. STUDY DESIGN Page 11 of 43 There were 5 amendments to the protocol. These amendments included:

( 1) A local laboratory could not be found to analyze the blood samples the same day of sample collection therefore additional sample collection procedures were instituted to account for proper sample storage and shipping. Additionally, clarifications were made to the procedure for worker illness, injury or manifestation of illness and acquiring medical attention. Changes were made with the informed consent, changing the criteria for determining when a worker should be transported to a hospital emergency room and subsequent allowable return to work.

( 2) Minor changes were made concerning the application rate to accommodate water soluble bag packaging. Application of test substance timing was changed from an 8AM deadline to an 11AM deadline. Leaf punch size was clarified ( diameter size of the leaf punch discs was 2.5 cm). The addition of Day 7 sampling interval for DFR sampling was included, and additional field fortification levels were included. . Urine aliquot preparation was changed from the field site to the analytical lab and additional urine control sampling fortifications were included.

( 3) A plan was instituted for possible reentry on day 2 postapplication to allow flexibility in accommodating rain or forecast rain. This amendment was instituted. The currently registered and marketed label allows reentry at one day postapplication.

( 4) The protocol called for estimating the urine volumes when collected and this was changed to making exact urine volume measurements at the analytical laboratory. Changed the DFR sampling protocol from ARTF SOPs to SEAgR SOPs. Changing the collection of DFR field fortification samples to only days the treated plot is sampled after the second application. Changing the number of non treated DFR samples collected from 5 to 3. Starting on Day 4, the urine samples were jointly spiked with sulfonyl and sulfinyl metabolites. The pH of the spray solution was not adjusted to less than or equal to 7. Another orchard of peaches was treated nearby with phosmet in case additional trees were needed to keep the thinners busy. Ten, rather than five DFR samples were collected from the treated plot on the day of reenty.

( 5) This amendment provided additional information about the laboratory used for creatinine analysis.

The protocol was amended to include a storage stability study of phosmet urinary metabolites in urine for storage intervals of one week and two weeks at freezer temperature. The protocol was also amended to change the urine storage stability fortification set such that each urine storage stability sample would be fortified with both phosmet urinary metabolites instead of fortifying each metabolite to separate urine samples.

A list of protocol deviations include: ( 1) the sodium sulfate was not heated in a muffle furnace at 600 º C for 2 hours prior to use, ( 2) 50 mL of DFR solution was fortified when preparing fortified control samples rather than the specified 200 mL, ( 3) 125 mL separatory funnels were used for partitioning rather than 250 mL separatory funnels, ( 4) a 15 meter DB 5MS column was used not a 10 or 20 meter column. The Study Author states that these deviations would have no impact on the study.

1. Test Site: The test site was a peach orchard located in Morven, near Valdosta, Georgia. The orchard contained approximately 17.5 acres with 45 rows of peach trees. Each tree was planted 16 ft apart and each row was spaced 19 ft apart. The variety of peach was Florida Crest and the trees were 4 years old. The mature trees ( approximately 7 ft tall) had a very good crop that required thinning. Many of the leaves were > 2.5 cm in width. The entire orchard was used as the test plot and according to the Study Report subplots were not necessary.

The orchard received no applications of cholinesterase inhibiting pesticides during the field phase of the study other than the monitored phosmet applications. Typical cultural practices were employed at the site.

2. Meteorology: Page 12 of 43 Meteorological conditions were recorded during the applications. Temperature and rainfall data were collected on site with automated Hobo monitors. According to the Study Report, the weather was favourable for both application dates. This information is provided in Table 1. The Study Report also noted that there was no precipitation or overhead irrigation during the period between the second application and the day of monitoring. Temperatures on the day between application and monitoring ranged from 48 to 82oF.

On the day of the reentry thinning tasks, the weather was mixed clouds and sun, with temperatures rising from 69 to 83oF with the relative humidity ranging from 67% to 90%. The relative humidity data was obtained from the Dixie, GA site of the Georgia Automated Weather Network located approximately 13 miles from the test site. In the afternoon of the reentry day, postapplication activities were cut short due to a significant rain event. Workers completed their morning work at noon and then took a break for lunch. They returned to the fields around 1: 20 PM. Two hours later, a thunderstorm forced the subjects to take cover in vehicles for about 25 minutes. They then reentered the fields even though it was raining lightly. The rain intensity increased, and after less than 25 minutes, the subjects had to cease work, leave the orchard, and return to the staging area. On site rainfall data collected with automated Hobo monitors reported 0.32 inches of rainfall on 31 March, the day of reentry. During the next two days, 2.09 and 0.02 inches of rain fell. Table 2 provides rainfall data for the duration of the study.

Table 1. Meteorological Conditions During Applications Parameter First Application ( 3/ 15/ 05) Second Application ( 3/ 29/ 05)

Air Temperature ( oF) 52 to 73 50 to 77 Wind Speed ( mph) 0 to 6 2 to 11 Percent Cloud Cover Overcast Clear skies Table 2. Rainfall Events for Duration of Study Date Activity Rainfall ( inches)

March 15, 2005 First Application 0.38 March 16, 2005 2.23 March 17, 2005 0.05 March 22, 2005 1.40 March 23, 2005 0.03 March 25, 2005 0.70 March 26, 2005 1.48 March 27, 2005 0.26 March 28, 2005 0.01 March 29, 2005 Second Application Pre App DFR Sampling 0 March 30, 2005 1DAT DFR Sampling 0 March 31, 2005 Reentry Exposure Monitoring 2DAT DFR Sampling 0.32 April 1, 2005 3DAT DFR Sampling 2.09 April 2, 2005 4DAT DFR Sampling 0.02 April 3, 2005 5DAT DFR Sampling 0 April 4, 2005 6DAT DFR Sampling 0 3. Number and type of workers: Page 13 of 43 Sixteen workers made up of both men and women were monitored for this study. The work crew was made up of 14 annual temporary immigrants from Mexico and two permanent residents employed as farm workers. The Study Report stated that the workers were not exposed to phosmet or any other cholinesterase inhibiting pesticides on workdays before and after the 2 day REI. Each worker was identified by a letter of the alphabet ( A through R). The workers ranged in age from 17 years to 60 years. The weight of the workers ranged from 47.7 kg to 117.7 kg. The workers' years of experience ranged from < 1 year to 8 years. All of the workers had thinning experience, except for M, N, R, and S, who were trained the day before the reentry event. All of the workers were provided with an informed consent form to read and sign prior to the start of the study.

4. Exposure Replicates: At the beginning of the study there were 16 workers selected to participate and each worker was identified by a letter of the alphabet ( A through R). Workers H and K dropped out of the study before any samples were collected. Each worker was monitored for 9 days. The one day of exposure occurred on the second day after the second seasonal application. Peach tree thinning postapplication activities took place 2 days after the airblast application of 3.0 lb ai/ A of phosmet to the test site. Each worker was assigned to his/ her own row for thinning. A record of trees thinned and any other noteworthy events was recorded. The morning shift began in the orchard a few minutes after 8: 00 AM and productivity was considered normal. The workers left the orchard at noon for lunch. The workers returned to the orchard by 1: 20 PM. The afternoon shift was unremarkable until a thunderstorm forced the workers to take cover in vehicles from 3: 25 PM to 3: 40 PM, at which time they re entered the orchard to continue with their thinning tasks. It was raining lightly, but the crew foreman indicated that they would normally work in this weather. The rain intensity increased, and by 4: 05 PM the workers left the orchard for the day. Total working time was approximately 6 hours before the rainfall and 25 minutes in the rain. The Study Report states that productivity for this sampling event was " considered typical." The workers were issued clean, dry clothing when they returned to the staging area. Some of the workers changed clothing immediately, and others waited until reaching their living quarters before changing. Pages 103 through 115, in the Study Report, provide observations of the workers recorded during the study.

5. Protective clothing: The Study Report states that the workers wore their own clothing. Table 3 outlines the clothing worn by the individual workers. A few of the workers wore jackets for part of the workday, some of the workers wore gloves, some wore hats, some workers wore short sleeved shirts and others wore long sleeved shirts.

Table 3. Test Subjects and Clothing Worn During Exposure Event Replicate Clothing Notes A Denim jacket, long sleeves, brimmed hat, leather shoes, socks, denim pants Jacket removed after lunch B Long sleeves, cap, socks, leather shoes, twill pants C Long sleeves over short sleeves, cap, socks, soft shoes, corduroy pants Sleeves rolled up after 25 minutes working, jacket after rain started D Coat, long sleeves shirt, socks, soft shoes, khaki pants Removed jacket and tied around waist, and went to short sleeves after 10 minutes working, jacket totally removed after 2 hours working and put on again after rain E Long sleeves, socks, soft shoes, jeans F 2 short sleeved shirts, cap, socks, soft shoes, jeans G Long sleeved shirt over other shirt, socks, leather shoes, linen pants Removed long sleeved shirt and tied around waist after lunch, put jacket back on after rains started I Short sleeves over knit shirt, cap, jeans, leather shoes, Page 14 of 43 Replicate Clothing Notes J Jacket, jeans, long sleeved shirt, socks, tennis shoes, cap, Jacket removed and tied around waist , longsleeves pushed up ( after 2 hours work)

L Long sleeved shirt, jeans, cap, socks, tennis shoes, one glove ( jersey weave), bandana at neck Took off glove at some point in the afternoon M Long sleeved shirt, jeans, cap, tennis shoes and tshirt N Short sleeved t shirt, cap, jeans, socks hiking boots O Short sleeved collared shirt, pants, cap, socks, tennis shoes P Short sleeved t shirt, cropped pants above ankle, tennis shoes, cloth gloves Q Long sleeved shirt, jeans, socks, work boots, cap R Long sleeved collared shirt, jeans, boots, socks, cap Long sleeves cuffed up or rolled back and forearms exposed 6. Application Method and Rate:

Application rate( s): Two foliar applications were made at 3.0 lb ai/ A on March 15, and March 29 of 2005. According to EPA Reg No. 10163 169, the maximum application rate is 4.25 lb ai/ A per application.

Antifoaming agents were used at a rate of 2 to 3 fluid ounces of antifoaming agent per tank load. During the second application, the pH was adjusted from 8.0 to 6.0 with Quest at a rate of 0.5 pints per 100 gallons.

Application Equipment: The applications were made according to usual agricultural practice, using the orchard owner's equipment driven by an experienced employee. The applications were made with a new Durand Wayland AF505 airblast sprayer driven by the power take off from a John Deere 2750 diesel tractor. The 500 gallon tank had 2 manifolds, each with 8 nozzles operating at approximately 185 200 pounds per square inch pressure.

Spray Volume: The spray volume was reported to be approximately 77.5 or 74.2 gal finished spray per acre. According to the product label, the test substance should be applied using an adequate spray volume to cover the foliage.

Equipment Calibration: According to the Study Report, the sprayer was calibrated before each application by the time/ distance/ volume output method with a verified flowmeter to achieve a nominal rate of 3 lb ai/ A.. Based on recorded pass times versus pass times calculated for the row lengths, 96% and 100% of the nominal application rate were achieved in the first and second applications, respectively.

7. Exposure monitoring methodology:

Urine: Each subject was issues an insulated cooler containing two labelled 1 L high density polyethylene screw cap wide mouth bottles for urine collection and two frozen gel packs. The coolers were issued at the beginning of the monitoring day and collected at the close of the monitoring day. A second cooler with empty bottles was issued at the close of the monitoring day for the collection of night voids and the first morning void. The two samples comprised one urine monitoring day. Urine samples were placed into a freezer at Page 15 of 43 the staging area, transferred to freezers at SEAdR, and stored frozen until they were shipped frozen to PTRL West via a FedEx freezer truck.

8. Dislodgeable Foliar Residue Sampling Procedures Method and Equipment: Samples were collected with a Birkestrand type leaf punch sampler with a disk diameter of 2.54 cm ( 1 inch).

Sampling Procedure: The leaf samples were collected directly into prelabelled glass jars using a Birkestrand type leaf punch sampler. Each sample consisted of a target of 40 leaf disks. The leaf disk sampler was cleaned with water and then acetone between each subsample. Sample jars were placed into coolers containing " blue ice" in the field and were dislodged within 4 hours of collection. Additional nontreated control samples were collected from nontreated orchards ( location not specified).

Surface area sampled ( two sides): The double sided surface area per leaf punch was approximately 10 cm2.

Total Surface Area per Replicate: The total surface area per replicate was approximately 405 cm2.

Replicates per activity:  Replicates per sampling time: Each sample consisted of 40 leaf disks.

 Number of sampling times: Five replicate samples were collected one day before the second application( ED  3), and one day after the second application ( ED  1). Ten replicate samples were collected on the monitoring day ( ED 0; 2 days postapplication). The Study Author also collected DFR replicates on the 4 days following reentry, resulting in a total of 7 sampling days.

Times of sampling: The exact time of day used for DFR sampling was not reported.

Part( s) of foliage sampled: The samples were collected from the leaves of the trees.

C. ANALYTICAL METHODOLOGY:

1. Sample Extraction/ Detection:

Urine:

Extraction method: The urine samples were analyzed for sulfinyl and sulfonyl phosmet urinary metabolites using a KMnO4 oxidation reaction followed by C18 Solid Phase Extraction cleanup allowing for a single moiety analysis of sulfonyl by LC/ MS/ MS.

Detection methods: Sample analysis was performed using SCIEX 3000 Components ( HPLC/ Turbo Ion Spray Mode). See Table 4 for specific conditions.

Table 4. Summary of LC/ MS/ MS Conditions for Urine Mode HPLC/ Turbo Ion Spray GC Column Supelco Supelcosil LC 318 ( 25 cm x 4.6 mm, 5 µ m with Supelcosil LC Page 16 of 43 Table 4. Summary of LC/ MS/ MS Conditions for Urine 318 pre column Solvents Solvent A = Water ( 0.05% formic acid) Solvent B = Acetonitrile ( 0.05% formic acid)

Time ( min.) Flow Rate ( mL/ min.) % A % B 0 0.50 98 2 13.0 0.50 37 63 13.5 1.3 0 100 17.0 1.3 0 100 17.5 1.0 98 2 25.0 1.0 98 2 25.5 0.5 98 2 Solvent Program 26.0 0.5 98 2 Injection Volume 10 µ L Ionization mode Turbo spray Divert valve to mass spectrophotometer On at 10.8 minutes, off at 13.0 minutes Retention Time Sulfinyl = 11.6 minutes Sulfonyl = 12.3 minutes Method Validation: The analytical facility developed methods for the SI and SO metabolites of phosmet in human urine using an oxidation reaction ( SI to SO) with KMnO4 followed by a C18 Solid Phase Extraction cleanup allowing for single moiety analysis of sulfonyl by LC/ MS/ MS. The analytical laboratory confirmed methods of analysis for the matrices and fully supported the analysis of samples with controls and procedural recoveries. The full method validation report is provided at the end of the study.

Instrument performance and calibration: To determine instrument calibration, each injection sequence was typically set up as follows: test standard injection, 0.02 µ g/ mL sulfonyl calibrant, solvent blank ( 1: 9 acetonitrile: water), and a control urine sample. After that run, the sequence alternated a calibrant injection and three or four extract samples ( including fortified control extracts, concurrent fortification extracts, field fortification extracts and urine donor sample extracts). The final injection for each sample set sequence was a quality control calibrant injection used to assess the stability of the calibrant response. Representative sulfinyl and sulfonyl calibration curves and LC/ MS/ MS calibrant chromatograms are presented in the study.

Quantification: The mass spectra data was collected and quantitation was based on the peak area of the daughter ion with m/ z 176 from the parent ion m/ z 256 ( sulfonyl). The transition of 240/ 176 amu was monitored for confirmation of complete oxidation during the sample Page 17 of 43 workup. The limit of quantitation for urine analysis was 0.025 µ g/ mL for each analyte or 0.516 µ g/ mL for the sulfonyl equivalence. Blood:

Sample Preparation: Blood samples were analyzed for plasma and red blood cell cholinesterase activity. A qualified local laboratory could not be located to perform the cholinesterase assays and due to concerns about the custody and integrity of the blood samples, the Study Director and Sponsor's Representative chose to fractionate the blood samples into plasma and saline washed packed red blood cells; freeze the samples; and ship the frozen samples to a qualified facility at the conclusion of the field phase of the study. The time from last venipuncture to placement into the mobile freezer was less than four hours.

Analysis: The plasma samples were assayed on 20 April using the Ellman photometric method. The red blood cell ( RBC) samples were analyzed for RChe on 20 and 21 April also using a method based on the Ellman method.

Dislodgeable Foliar Residues:

Dislodging Procedure: The residues from the leaf disks were dislodged within 4 hours of collection. Residues were dislodged twice, each time with 100 mL of 0.01% Aerosol OT in distilled water. Each sample was placed on a reciprocating shaker operated at approximately 200 cycles per minute for 10 minutes. The leaf disks were counted and discarded after the final dislodging and both 100 mL solutions were combined into a single sample for analysis. The samples were placed in frozen storage until shipment to the analytical laboratory.

Detection methods: The DFR samples were analyzed by GC FPD using a Model No. 6890 Hewlett Packard Gas Chromatograph equipped with a Hewlett Packard Flame Photometric Detector ( FPD) See Table 5 for specific conditions.

Table 5. Summary of GC FPD Operating Conditions Column DB 5MS Capillary Column 15m x 0.53 mm i. d. x 1.5 µ m film thickness Gas Flow Rates Carrier: 72.0 mL/ min. ( Helium) Detector: 133 mL/ min. ( Hydrogen) Detector: 128 mL/ min. ( Air) Detector Makeup: 74 mL/ min. ( Nitrogen)

Injector Temperature 220 ° C Detector Temperature 225 ° C Injection Volume 4 µ L, by Hewlett Packard 7683 Autosampler Inlet Conditions Injection port liner: single gooseneck liner with Restek carbofrit insert. Splitless, purge flow 2 mL/ min. @ 2 minutes.

Oven Temperature Program Initial Temperature: 160 ° C for 1 minute Ramp: 160 ° C to 260 ° C at 15 ° C/ minute ( hold 2 minutes) Retention Time: ~ 5.3 minutes for Phosmet; ~ 4.7 minutes for Phosmet oxon Page 18 of 43 Method validation: PTRL West validated an existing analytical method for the determination of phosmet and phosmet oxon in foliar dislodging solution. Method validation recoveries ranged from 84.5% to 90.2% for phosmet and from 88.8% to 93.2% for phosmet oxon.

Instrument performance and calibration: A linear regression of the calibration solutions peak area vs. concentration for each analyte was determined and used to calculate the concentration of phosmet and phosmet oxon in the DFR samples. Sample injections were bracketed by calibration solution injections or a quality control calibrant solution injection. Quality control calibrant injections were analyzed last and compared to the relevant calibrant injections used in the quantitation to assess the stability of the responses.

Quantification: The analytes were identified by the coincidence of their retention times with that of reference standard calibration solutions. Phosmet and phosmet oxon were quantified by integration of the GC/ FPD peak areas for each analyte in the samples. The limit of quantitation for DFR samples is 1.0 µ g/ mL for phosmet and 0.2 µ g/ mL for phosmet oxon.

2. Quality Control:

Lab Recovery:

Urine: Concurrent laboratory urine fortification sample recoveries are summarized in Table 6 below. Each sample set included two concurrent fortified urine samples fortified with both sulfinyl and sulfonyl. The fortification levels were the following: 0.025 µ g/ mL, 0.05 µ g/ mL, 0.10 µ g/ mL, and 0.25 µ g/ mL. In addition, each sample set ( except day 1 and 2) included two fortified control urine extract samples that were fortified with sulfonyl only, at 0.5 µ g/ mL and 0.2 µ g/ mL. The control urine used for each sample set was an unfortified field fortification sample. Concurrent fortification sample recoveries ranged from 62% to 119% with an overall recovery of 90 ± 14% recovery. Control extract fortification sample recoveries ranged from 76% to 122% with an overall recovery of 104 ± 10%.

Table 6. Concurrent Laboratory Urine Fortification Recoveries Urine Sample Set Sulfinyl Fortification ( ug/ mL) Sulfonyl Fortification ( ug/ mL) Total Sulfonyl Fortification Equivalence ( ug/ mL) 1 Sulfonyl Detected ( ug/ mL) Sulfonyl Recovery (%)

0.025 0.025 0.052 0.046 90% Days 1 and 2 0.05 0.05 0.103 0.083 80% 0.025 0.025 0.052 0.055 106% Day 2A 0.25 0.25 0.517 0.389 75% 0.025 0.025 0.052 0.054 104% Day 2B 0.25 0.25 0.517 0.433 84% 0.025 0.025 0.052 0.052 101% Day 4A 0.25 0.25 0.517 0.429 83% Day 4B 0.025 0.025 0.052 0.060 117% Page 19 of 43 Table 6. Concurrent Laboratory Urine Fortification Recoveries Urine Sample Set Sulfinyl Fortification ( ug/ mL) Sulfonyl Fortification ( ug/ mL) Total Sulfonyl Fortification Equivalence ( ug/ mL) 1 Sulfonyl Detected ( ug/ mL) Sulfonyl Recovery (%)

0.25 0.25 0.517 0.469 91% 0.025 0.025 0.052 0.055 106% Day 5A 0.25 0.25 0.517 0.395 77% 0.025 0.025 0.052 0.061 118% Day 5B 0.25 0.25 0.517 0.459 89% 0.05 0.05 0.103 0.094 91% Day 6A 0.25 0.25 0.517 0.427 83% 0.05 0.05 0.103 0.095 92% Day 6B 0.25 0.25 0.517 0.403 78% 0.05 0.05 0.103 0.092 89% Day 7A 0.25 0.25 0.517 0.410 79% 0.025 0.025 0.052 0.050 97% Day 7B 0.1 0.1 0.207 0.179 86% 0.10 0.1 0.207 0.129 62% Day 8A 0.025 0.025 0.052 0.036 69% 0.025 0.025 0.052 0.048 93% Day 8B 0.10 0.1 0.207 0.148 72% 0.025 0.025 0.052 0.055 106% Day 9A 0.10 0.1 0.207 0.182 88% 0.025 0.025 0.052 0.058 112% Day 9B 0.10 0.1 0.207 0.165 80% Average 90% Std. Dev. 14% 1 Total sulfonyl equivalence = sulfonyl fortification ( µ g/ mL) + ( sulfinyl fortification ( µ g/ mL) x ( 257/ 241) where 257/ 241 = the molecular weight ratio of sulfonyl ÷ sulfinyl.

DFR: Concurrent laboratory DFR fortification sample recoveries are summarized in Table 7. Each sample set included two concurrent fortified DFR samples and a control sample. Duplicate concurrent fortification samples were analyzed with each set; each sample in the set was fortified with phosmet and phosmet oxon. For set 1, the concurrent fortification samples were fortified at 1.0 µ g/ mL phosmet and 0.2 µ g/ mL phosmet oxon. For sets 2 through 7, the concurrent fortification samples were fortified at 10.0 µ g/ mL phosmet and 2.0 µ g/ mL phosmet oxon. Overall recovery of phosmet and phosmet oxon from all concurrent fortification samples was 88.2 ± 2.8% and 98.4 ± 4.2%, respectively. No phosmet or phosmet oxon was detected in the control sample analyzed with each set, with the exception of set 4 and set 5 where 0.13 µ g and 0.12 µ g phosmet was detected. For these sets, concurrent fortification recoveries were corrected for the phosmet detected in the control samples. Page 20 of 43 Table 7. Concurrent Laboratory DFR Fortification Recoveries Fortification Level Percent Recovered Sample Set Phosmet ( ug/ mL) Phosmet Oxon ( ug/ mL) Phosmet Detected ( ug/ mL) Phosmet Oxon Detected ( ug/ mL) Phosmet Detected ( ug/ cm2) Phosmet Oxon Detected ( ug/ cm2) Phosmet Phosmet Oxon 1.0 0.2 0.902 0.196 0.445 0.097 90.2% 98.0% DFR set 1 1.0 0.2 0.920 0.198 0.454 0.098 92.0% 99.0% 10.0 2.0 9.205 1.862 4.546 0.920 92.1% 93.1% DFR set 2 10.0 2.0 9.153 1.841 4.520 0.909 91.5% 92.1% 10.0 2.0 8.568 2.003 4.231 0.989 85.7% 100.2% DFR set 3 10.0 2.0 8.918 2.049 4.404 1.012 89.2% 102.5% 10.0 2.0 8.591 2.102 4.242 1.038 85.9% 105.1% DFR set 4 10.0 2.0 8.411 2.098 4.154 1.036 84.1% 104.9% 10.0 2.0 8.396 2.000 4.146 0.988 84.0% 100.0% DFR set 5 10.0 2.0 8.651 2.002 4.272 0.989 86.5% 100.1% 10.0 2.0 8.600 1.818 4.247 0.898 86.0% 90.9% DFR set 6 10.0 2.0 8.908 1.947 4.399 0.961 89.1% 97.4% 10.0 2.0 8.936 1.975 4.413 0.975 89.4% 98.8% DFR set 7 10.0 2.0 8.978 1.927 4.434 0.952 89.8% 96.4% Average 88.2% 98.4% Std. Dev. 2.7% 4.2%

Field recovery:

Urine: Urine field fortification samples were analyzed on ED 6, ED 5, ED 2, ED+ 0, ED+ 1, ED+ 2, ED+ 3, and ED+ 4. For ED 6 field fortification samples, a control and two samples fortified in the field with sulfinyl only and two samples fortified in the field with sulfonyl only were analyzed. For ED 5 samples, a control and one sample fortified with both analytes and two samples fortified with either sulfinyl or sulfonyl only were analyzed. For days ED+ 0 through ED+ 4 samples, a control sample was analyzed as well as duplicate field fortification samples fortified with sulfinyl and sulfonyl at two levels. No detectable residues were found in the control field fortification samples analyzed.

The Study Author excluded seven samples with recovery values < 50% from their overall field fortification recovery. Excluding these apparently misfortified samples, the Study Author reported an overall field fortification recovery of 103 ± 15%. Versar included all reported recovery values, which resulted in an overall field fortification recovery of 84 ± 38% recovery. A summary of the field fortification recoveries are reported in Table 8. Page 21 of 43 Table 8. Urine Field Fortification Samples Collection Day ( postapp.) Urine Volume ( mL) Sulfinyl Fortification ( ug) Sulfonyl Fortification ( ug) Total Sulfonyl Fortification Equivalence ( ug) 1 Sulfonyl Detected ( ug) 2 Percent Recovered 520 25 0 26.7 32.6 122% 465 50 0 53.3 52.8 99% 420 0 15 15.0 17.2 115% ED 6 507 0 25 25.0 26.7 107% 505 25 15 41.7 43.6 105% 526 0 50 53.3 54.7 103% ED 5 470 25 0 25.0 25.1 100% 536 25 15 41.7 54.7 131% 492 50 25 78.3 7.0 9% 568 25 15 41.7 45.7 110% ED 2 440 50 25 78.3 89.0 114% 538 125 60 193.3 206.7 107% 515 125 60 193.3 192.0 99% 440 250 100 366.6 396.5 108% ED+ 0 457 250 100 366.6 347.5 95% 435 250 100 366.6 318.5 87% 440 125 60 193.3 197.0 102% 325 125 60 193.3 27.6 14% ED+ 1 508 250 100 366.6 350.0 95% 407 125 60 193.3 213.8 111% 487 250 100 366.6 428.8 117% 440 250 100 366.6 179.3 49% ED+ 2 508 125 60 193.3 59.0 31% 352 50 25 78.3 70.2 90% 502 25 15 41.7 32.3 78% 315 25 15 41.7 5.3 13% ED+ 3 350 50 25 78.3 5.2 7% 521 25 15 41.7 44.9 108% 440 50 25 78.3 8.1 10% 480 50 25 78.3 47.8 61% ED+ 4 507 25 15 41.7 46.6 112% Average ( excluding the fortification with values < 50%) 103% Std. Dev 15% Average ( including all samples) 84% Std. Dev. 38% 1 Total sulfonyl equivalence = sulfonyl fort. ( ug/ mL) + sulfinyl fort. ( ug/ mL) x ( 257/ 241) where 257/ 241 = the molecular weight ratio of sulfonyl/ sulfinyl 2 The sulfonyl values reported for the first two days postapplication in Table VII ( page 181) of the study report differ from the values presented in Table 7 ( page 32) of the redacted report. Versar was informed by the study author that the values reported in the redacted report were incorrect due to data entry error; therefore; the values reported in this table are from Table VII ( page 181) of the study report. Page 22 of 43 DFR DFR field fortification samples were collected from monitoring days ED 6, ED 5, ED+ 2, ED+ 3, and ED+ 4. For each of these days, a control field fortification sample was analyzed as well as two field fortification samples fortified with phosmet only ( at two different levels) and two samples fortified with phosmet oxon only ( at two different levels). No detectable residues were found in the day ED 6 and ED 5 control field fortification samples analyzed. Low levels of phosmet were detected in day ED+ 2, ED+ 3, and ED+ 4 control field fortification samples (< 0.01 µ g/ mL).

The study author excluded one sample with a recovery values of 25.1% from their overall field fortification recovery. Excluding this outlier, the study author reported an overall field fortification recovery of 83.0% for phosmet and 91.7% for phosmet oxon. A summary of the field fortification recoveries are reported in Table 9.

Table 9. DFR Field Fortification Recoveries Fortification ( ug/ mL) Residues Detected ( ug/ mL) Fortification ( ug/ cm2) Residues Detected ( ug/ cm2) Percent Recovery Collection Day DFR Volume ( mL) Phosmet Phosmet Oxon Phosmet Phosmet Oxon Phosmet Phosmet Oxon Phosmet Phosmet Oxon Phosmet Phosmet Oxon 198 8.84 6.828 4.365 3.372 77.3%

200 10.00 9.085 4.938 4.486 90.9%

196 0.026 0.024 0.013 0.012 94.1% ED 6 198 0.025 0.025 0.012 0.012 99.0%

196 7.65 6.515 3.779 3.217 85.1%

193 9.07 7.130 4.478 3.521 78.6%

196 0.026 0.025 0.013 0.012 98.0% ED 5 193 0.052 0.039 0.026 0.019 75.3%

192 5.21 3.002 2.572 1.482 57.6%

195 6.41 4.766 3.166 2.354 74.3%

192 0.052 0.043 0.026 0.021 82.6% ED+ 2 192 0.078 0.063 0.039 0.031 80.6%

195 3.85 0.964 1.899 0.476 25.1%

200 5.00 4.262 2.469 2.105 85.2%

190 0.079 0.050 0.039 0.025 63.3% ED+ 3 194 0.103 0.093 0.051 0.046 90.2%

197 3.81 2.906 1.880 1.435 76.3%

196 5.10 3.879 2.520 1.916 76.0%

197 0.076 0.056 0.038 0.028 73.5% ED+ 4 196 0.102 0.082 0.050 0.040 80.4%

Average Recovery ( excluding sample < 50%) 83.0% 91.7%

Tank mix: Tank mix samples were not collected during the application of the test product.

Travel Recovery: Information on travel recovery was not reported. Page 23 of 43 Storage Stability: The study author reported that the sulfonyl analyte was found to be stable in the final extracts when stored for 18 days in a freezer. Field fortification sample extracts from day 4 were re analyzed with the day 8B sample set. Re analysis of the extracts for concurrent fortified samples 1 and 2 and day 4 field fortification gave recoveries of 99%, 80% and 114%, respectively where initial analysis gave recoveries of 102%, 83% and 110%, respectively. All final extract samples were analyzed within 18 days of extraction and were stored in a freezer when not analyzed directly.

II. RESULTS AND CALCULATIONS:

A. EXPOSURE CALCULATIONS:

Urinary Metabolites Phosmet equivalent residue was estimated by the Study Authors by measurement of the sulfonyl and sulfinyl metabolites of phosmet in 24 hour urine samples collected for five consecutive days beginning on the morning of postapplication reentry. The Study Authors report that worker compliance with collection of 24 hour urine samples was " excellent to poor". They discuss the difficulties encountered in getting some of the workers to comply with proper collection procedures. This difficulty led to the use of multipliers to adjust metabolite concentrations for incomplete sample collection. The Study used a creatinine correction strategy outlined in Mage et. al. ( 2004). Expected creatinine concentration was modelled as a function of a person's age, gender, and body surface area according to the following formulas:

Male µ g Cn/ day = 1.93( 140 age[ year]) * wt[ kg] 1.5* ht[ cm] 0.5 Female µ g Cn/ day = 1.64( 140 age[ year]) * wt[ kg] 1.5* ht[ cm] 0.5 Urinary creatinine levels determined in the samples was compared to the expected urinary creatinine for each individual at each sampling event. Based on this estimate of expected creatinine, an adjustment factor ( ranging from 0.64 to 4.38) was applied to the sulfonyl concentration in each urine collection and residues were estimated by:

Creatinine adjusted sulfonyl = measured sulfonyl * adjustment factor Reported phosmet equivalents ( ug/ day) = corrected SO ( ug/ day) * adjustment factor * 1.235 molecular weight conversion to phosmet equivalents. Molecular weight of phosmet ( 317.33) and molecular weight of sulfonyl ( 257). No pharmacokinetic factors were utilized in this calculation.

Table 10 provides a summary of SO residues assayed in the urine samples and the corresponding creatinine adjusted potential phosmet equivalents excreted per day as calculated by the Study Author. The reported phosmet equivalents do not take into consideration the pharmacokinetics of phosmet metabolism. Over half of the pre exposure samples showed no detectable level of SO residue in the urine. The total post exposure phosmet equivalents ranged from 1031 µ g/ day ( worker G) to 9488 µ g/ day ( worker J). The highest daily concentrations was generally found on the first exposure day ( ED 0), although four of the sixteen workers demonstrated the highest urine levels on the second exposure day ( ED + 1). Levels steadily decreased during the monitoring period; however, the levels did not reach preexposure levels by the end of the sample collection period.

Cholinesterase Activity A laboratory qualified to perform immediate cholinesterase assays was not available near the test site. Therefore the Study Director chose to separate the blood samples into plasma and red blood cells. The red blood cells were washed with saline and both fractions were stored and shipped frozen to LabCorp in North Carolina. The samples were assayed on 20 and 21 April using assays based on the Ellman photometric method. Page 24 of 43 Plasma Cholinesterase Activity:

Plasma samples were divided into two sets ( subsample set " a" and subsample set " b"). All subsample " a" tubes were assayed along with randomly selected subsample " b" tubes (~ 19%). The 27 duplicate samples ( subsample " b") averaged 0.4% greater than the corresponding " a" subsamples, with a standard deviation of ± 2.4%. Mean values ranged from 2,699 U/ L ( ED  2) to 3,406 U/ L ( ED + 1). An analysis of variance showed no significant differences between days for the subsample " a" assays. The activity of the positive ChE controls at the beginning and end of the run ( 2 each) were near the expected mean and were well within specifications. The Study Author reported no remarkable findings and no exposure related depression of PChe. A summary of the results is presented in Table 10.

Red Blood Cell Cholinesterase Assays:

Mean values of the RChe samples ranged from 2,849 U/ L ( ED  6) to 5,229 U/ L ( ED + 4). The study director noticed that the SOP was not being followed after the first set of 28 had been prepared. The technician attempted to recover the samples and hemolyze the samples, but forgot the vortexing steps. There was also a concern that a vortexing step might have been left out of the remaining samples. Therefore, the results of the first 28 samples were compromised and there was uncertainty about the remaining samples. The study author decided to complete a subsample " b" set the following day. A summary of the results is presented in Table 10. The RChe results were more variable than the PChe results. The RChe activity on ED 6 was markedly lower than on other days. This was explained as normal population variance as the handling of samples was similar. An analysis of variance with and without the Bonferroni correction at the p=< 0.05 level showed some significant differences among some day wise comparisons. Most were associated with the lower values on ED  6. The Study Author reports no remarkable findings and no exposure related depression of RChe.

DFR:

Dislodgeable foliar residue ( DFR) was examined on the day before the second application, the day of the second application ( 2 days prior to reentry activity) and for the following five days ( i. e., 7 monitored days). The Study Author concluded that the continuing hard rain at the end of the exposure day had affected the dissipation kinetics and reported that a meaningful dissipation curve could not be developed. The residues on the day of second application and the following day demonstrated residues comparable to previous phosmet DFR studies. The phosmet DFR on days 1 and 2 postapplication averaged 5.9 ug/ cm2 and 5.0 ug/ cm2 , respectively. Phosmet oxon DFR on days 1 and 2 postapplication averaged 0.012 ug/ cm2 and 0.010 ug/ cm2 , respectively. DFR sampling also occurred on the subsequent 4 days. By the 6th day after application DFR levels declined to 0.7 ug/ cm2 and 0.004 ug/ cm2 for phosmet and phosmet oxon, respectively. A summary of the DFR results is presented in Table 11. The residue levels were corrected for field fortification recovery values. 25 TABLE 10. Summary of Postapplication Biomonitoring Data   Phosmet Treated Peach Trees Worker ID Clothing Body Weight kg Day of Collectiona 24 hour Urine Volumeb mL/ day Cnc mg/ mL Cn mg/ day Adjustment Factord SO residuee ug/ mL SO residuef ug/ day Reported Phosmet equivalentg ( ug/ day) Plasma ChE Activity ( U/ L) RBC ChE Activity ( U/ L)

ED 6 3,323 3,712 ED 5 295 1.12 330 4.38 0.045 13 72 3,425 5,384 ED 3 3,468 4,608 ED 2 920 1.27 1,168 1.24 0.016 15 23 3,289 5,151 ED 0 930 1.23 1,143 1.27 0.427 397 621 3,055 5,518 ED+ 1 1,140 0.97 1,102 1.31 0.181 206 335 3,354 4,369 ED+ 2 1,240 0.87 1,078 1.34 0.097 120 199 3,277 4,343 ED+ 3 1,070 1.00 1,075 1.35 0.042 45 75 3,408 5,022 A ( male)

Ht 168 cm Age 34 Denim jacket,

Long sleeves, hat,

denim pants, leather shoes ( Jacket removed after lunch) 66.8 ED+ 4 1,350 0.83 1,126 1.28 0.051 69 109 3,212 4,849 TOTAL POST EXPOSURE PHOSMET FOR WORKER A 1,339 ED 6 3,352 706 ED 5 1,430 1.24 1,773 1.36 0.047 67 113 3,499 4,120 ED 3 3,522 4,470 ED 2 1,450 1.22 1,769 1.36 0.024 35 58 3,354 4,683 ED 0 1,780 0.79 1,410 1.71 0.727 1294 2,728 3,432 4,987 ED+ 1 1,940 0.65 1,267 1.90 0.219 425 997 3,441 4,510 ED+ 2 1,710 1.00 1,705 1.41 0.17 291 507 3,553 4,857 ED+ 3 780 1.69 1,321 1.82 0.088 69 154 3,476 4,430 B ( male)

Ht 163 cm Age 28 Long sleeves,

cap, twill pants, leather shoes 91.4 ED+ 4 1,570 1.26 1,975 1.22 0.111 174 262 3,545 6,871 TOTAL POST EXPOSURE PHOSMET FOR WORKER B 4,648 26 TABLE 10. Summary of Postapplication Biomonitoring Data   Phosmet Treated Peach Trees Worker ID Clothing Body Weight kg Day of Collectiona 24 hour Urine Volumeb mL/ day Cnc mg/ mL Cn mg/ day Adjustment Factord SO residuee ug/ mL SO residuef ug/ day Reported Phosmet equivalentg ( ug/ day) Plasma ChE Activity ( U/ L) RBC ChE Activity ( U/ L)

ED 6 3,276 4,115 ED 5 215 1.47 316 4.29 0.043 9 49 3,343 5,233 ED 3 3,514 5,022 ED 2 550 1.85 1,018 1.33 0.009 5 8 3,471 5,577 ED 0 990 1.34 1,322 1.03 1.258 1245 1,579 3,168 5,884 ED+ 1 540 1.43 770 1.76 1.442 779 1,695 3,419 5,023 ED+ 2 670 1.22 819 1.66 0.701 470 961 NS NS ED+ 3 520 1.72 895 1.52 0.208 108 203 3,447 5,108 C ( male)

Ht 160 cm Age 19 Long sleeve over short sleeve shirt,

cap, cords,

soft shoes.

( Long sleeve shirt 59.5 ED+ 4 780 1.93 1,509 0.90 0.116 90 101 3,290 5,810 TOTAL POST EXPOSURE PHOSMET FOR WORKER C 4,539 ED 6 2,665 3,317 ED 5 650 0.83 540 2.87 0.032 21 74 2,780 4,834 ED 3 2,865 4,996 ED 2 950 1.53 1,454 1.07 0.018 17 22 2,679 5,259 ED 0 600 1.77 1,061 1.46 0.164 98 177 2,569 3,922 ED+ 1 1,295 1.37 1,775 0.87 0.599 776 836 2,658 4,853 ED+ 2 1,740 0.99 1,717 0.90 0.228 397 442 2,757 5,195 ED+ 3 1,540 1.02 1,572 0.98 0.105 162 197 2,720 5,252 D ( male)

Ht 160 cm Age 19 Coat, long sleeves,

khaki pants,

soft shoes.

( Jacket worn round waist   removed after 2 hrs work) 65 ED+ 4 1,630 1.13 1,848 0.84 0.095 155 160 2,590 5,624 TOTAL POST EXPOSURE PHOSMET FOR WORKER D 1,812 ED 6 3,258 3,158 ED 5 710 0.89 632 2.23 0.033 23 65 3,094 5,884 ED 3 3,381 4,548 ED 2 850 1.35 1,148 1.23 0.023 20 30 3,373 5,638 ED 0 690 2.40 1,653 0.85 0.582 402 424 3,258 5,200 ED+ 1 840 1.42 1,194 1.18 1.456 1223 1,786 3,218 5,305 ED+ 2 1,165 1.38 1,608 0.88 0.556 648 702 3,125 5,864 ED+ 3 510 1.17 598 2.36 0.374 191 556 3,287 4,712 E ( male)

Ht 160 cm Age 17 Long sleeves,

jeans, soft shoes 60.5 ED+ 4 1,050 2.10 2,210 0.64 0.066 69 55 3,102 4,702 TOTAL POST EXPOSURE PHOSMET FOR WORKER E 3,523 27 TABLE 10. Summary of Postapplication Biomonitoring Data   Phosmet Treated Peach Trees Worker ID Clothing Body Weight kg Day of Collectiona 24 hour Urine Volumeb mL/ day Cnc mg/ mL Cn mg/ day Adjustment Factord SO residuee ug/ mL SO residuef ug/ day Reported Phosmet equivalentg ( ug/ day) Plasma ChE Activity ( U/ L) RBC ChE Activity ( U/ L)

ED 6 3,121 3,303 ED 5 NS NS NS NS NS NS NS 2,985 5,327 ED 3 3,027 4,871 ED 2 1,400 1.01 1,414 1.23 0.019 27 40 3,065 4,539 ED 0 2,700 0.73 1,958 0.89 1.626 4390 4,811 3,009 2,585 ED+ 1 1,355 1.14 1,539 1.13 0.965 1308 1,823 2,862 5,111 ED+ 2 1,250 0.92 1,146 1.52 0.467 584 1,093 NS NS ED+ 3 1,150 1.18 1,354 1.28 0.284 327 518 3,170 4,715 F ( male)

Ht 165 cm Age 18 2 short sleeve shirts, cap,

jeans, soft shoes 69.1 ED+ 4 1,940 0.71 1,368 1.27 0.123 239 374 2,958 5,657 TOTAL POST EXPOSURE PHOSMET FOR WORKER F 8,619 ED 6 2,152 3,023 ED 5 720 1.47 1,058 1.63 ND ND ND 2,227 5,459 ED 3 2,558 5,853 ED 2 1,110 1.16 1,288 1.34 ND ND ND 2,347 5,337 ED 0 1,000 1.39 1,393 1.24 0.235 235 361 2,391 2,437 ED+ 1 1,410 1.18 1,658 1.04 0.234 330 425 2,323 5,702 ED+ 2 800 1.40 1,120 1.54 0.061 49 93 2,468 5,151 ED+ 3 710 1.66 1,182 1.46 0.041 29 53 2,532 6,135 G ( female)

Ht 145 cm Age 29 Long sleeve shirt, short sleeve shirt,

linen pants,

leather shoes ( long sleeve shirt put on after rains started) 85.5 ED+ 4 730 1.41 1,026 1.69 0.065 47 99 2,621 5,767 TOTAL POST EXPOSURE PHOSMET FOR WORKER G 1,031 28 TABLE 10. Summary of Postapplication Biomonitoring Data   Phosmet Treated Peach Trees Worker ID Clothing Body Weight kg Day of Collectiona 24 hour Urine Volumeb mL/ day Cnc mg/ mL Cn mg/ day Adjustment Factord SO residuee ug/ mL SO residuef ug/ day Reported Phosmet equivalentg ( ug/ day) Plasma ChE Activity ( U/ L) RBC ChE Activity ( U/ L)

ED 6 3,419 3,507 ED 5 1,350 1.25 1,688 0.86 0.038 51 54 3,315 5,813 ED 3 3,333 4,716 ED 2 1,055 1.32 1,393 1.04 0.013 14 18 3,538 5,023 ED 0 800 1.91 1,527 0.95 0.464 371 433 3,438 4,994 ED+ 1 1,023 1.51 1,542 0.94 0.658 673 778 3,384 5,255 ED+ 2 900 1.31 1,183 1.22 0.366 329 496 3,311 5,420 ED+ 3 550 2.62 1,439 1.00 0.05 28 34 3,201 4,622 I ( male)

Ht 160 cm Age 40 Short sleeves over knit shirt, cap,

jeans 70.5 ED+ 4 500 2.56 1,281 1.13 0.017 9 12 3,069 4,244 TOTAL POST EXPOSURE PHOSMET FOR WORKER I 1,753 ED 6 3,116 1,127 ED 5 1,435 1.13 1,622 1.01 ND ND ND 3,074 4,224 ED 3 3,236 5,123 ED 2 950 1.54 1,463 1.12 0.025 24 33 3,245 4,431 ED 0 1,555 0.95 1,476 1.11 2.625 4082 5,611 3,184 3,155 ED+ 1 1,925 0.86 1,650 1.00 0.768 1478 1,818 3,258 5,136 ED+ 2 2,050 0.81 1,658 0.99 0.385 789 966 3,300 4,716 ED+ 3 2,080 0.86 1,793 0.92 0.25 520 588 NS NS J ( male)

Ht 168 cm Age 34 Jacket Long sleeves,

cap, jeans,

tennis shoes ( Jacket removed after 2 hrs work) 72.7 ED+ 4 2,400 0.76 1,822 0.90 0.189 454 505 3,132 4,229 TOTAL POST EXPOSURE PHOSMET FOR WORKER J 9,488 29 TABLE 10. Summary of Postapplication Biomonitoring Data   Phosmet Treated Peach Trees Worker ID Clothing Body Weight kg Day of Collectiona 24 hour Urine Volumeb mL/ day Cnc mg/ mL Cn mg/ day Adjustment Factord SO residuee ug/ mL SO residuef ug/ day Reported Phosmet equivalentg ( ug/ day) Plasma ChE Activity ( U/ L) RBC ChE Activity ( U/ L)

ED 6 3,378 2,900 ED 5 1,650 0.66 1,089 1.44 0.035 58 102 3,317 4,725 ED 3 3,532 4,320 ED 2 930 1.08 1,004 1.56 0.034 32 61 3,424 4,658 ED 0 1,660 0.51 852 1.83 0.911 1512 3,426 3,541 4,493 ED+ 1 1,520 0.71 1,076 1.45 0.575 874 1,568 3,453 5,041 ED+ 2 635 0.91 579 2.70 0.333 211 705 3,298 4,707 ED+ 3 2,080 0.83 1,731 0.90 0.187 389 434 3,469 4,422 L ( male)

Ht 170 cm Age 19 Long sleeve shirt, cap,

jeans, bandana,

tennis shoes one glove ( glove removed in late afternoon) 64.1 ED+ 4 480 1.88 904 1.73 0.12 58 123 3,402 4,425 TOTAL POST EXPOSURE PHOSMET FOR WORKER L 6,256 ED 6 2,408 1,715 ED 5 1,325 0.67 888 0.80 ND ND ND 2,380 5,760 ED 3 670 1.40 938 0.76 ND ND ND 2,227 4,796 ED 2 2,321 5,045 ED 0 1,350 0.62 842 0.84 0.462 624 648 2,161 4,511 ED+ 1 600 0.34 205 3.46 0.118 71 302 2,555 5,500 ED+ 2 760 1.14 867 0.82 0.236 179 181 2,421 5,187 ED+ 3 1,020 1.08 1,105 0.64 0.1 102 81 2,281 4,410 M ( male)

Ht 160 cm Age 52 Long sleeves,

tshirt cap,

jeans,

tennis shoes 47.7 ED+ 4 1,130 0.79 898 0.79 0.069 78 76 2,402 5,711 TOTAL POST EXPOSURE PHOSMET FOR WORKER M 1,288 30 TABLE 10. Summary of Postapplication Biomonitoring Data   Phosmet Treated Peach Trees Worker ID Clothing Body Weight kg Day of Collectiona 24 hour Urine Volumeb mL/ day Cnc mg/ mL Cn mg/ day Adjustment Factord SO residuee ug/ mL SO residuef ug/ day Reported Phosmet equivalentg ( ug/ day) Plasma ChE Activity ( U/ L) RBC ChE Activity ( U/ L)

ED 6 2,411 3,949 ED 5 1,475 0.55 811 2.38 ND ND ND 2,325 5,167 ED 3 2,437 4,745 ED 2 340 1.71 581 3.32 ND ND ND 2,335 5,163 ED 0 950 1.31 1,246 1.55 1.392 1322 2,531 2,309 4,186 ED+ 1 810 1.12 909 2.12 0.237 192 504 2,329 4,979 ED+ 2 1,175 0.74 873 2.21 0.27 317 867 2,389 4,664 ED+ 3 1,075 0.94 1,007 1.92 0.247 266 629 2,405 4,185 N ( male)

Ht 168 cm Age 32 Short sleeves,

cap, jeans,

hiking boots 80 ED+ 4 1,160 1.33 1,547 1.25 0.224 260 401 2,521 5,429 TOTAL POST EXPOSURE PHOSMET FOR WORKER N 4,932 ED 6 2,528 1,686 ED 5 750 0.85 638 1.60 ND ND ND 2,698 6,254 ED 3 NS NS ED 2 517 1.38 713 1.43 ND ND ND 2,715 5,508 ED 0 620 0.95 587 1.73 1.934 1199 2,568 2,744 2,968 ED+ 1 660 0.69 458 2.22 0.767 506 1,389 2,788 4,532 ED+ 2 870 1.00 873 1.17 0.253 220 317 2,608 4,503 ED+ 3 740 0.83 616 1.65 0.131 97 198 2,564 5,607 O ( male)

Ht 155 cm Age 60 Short sleeves,

cap, pant,

tennis shoes 65.5 ED+ 4 760 0.63 478 2.13 0.169 128 338 NS NS TOTAL POST EXPOSURE PHOSMET FOR WORKER O 4,810 31 TABLE 10. Summary of Postapplication Biomonitoring Data   Phosmet Treated Peach Trees Worker ID Clothing Body Weight kg Day of Collectiona 24 hour Urine Volumeb mL/ day Cnc mg/ mL Cn mg/ day Adjustment Factord SO residuee ug/ mL SO residuef ug/ day Reported Phosmet equivalentg ( ug/ day) Plasma ChE Activity ( U/ L) RBC ChE Activity ( U/ L)

ED 6 2,893 3,963 ED 5 750 0.89 668 3.23 ND ND ND 2,958 4,950 ED 3 NS NS ED 2 517 1.38 713 3.03 0.021 11 41 2,766 4,361 ED 0 940 0.86 808 2.67 1.035 973 3,210 2,845 4,264 ED+ 1 1,270 0.90 1,139 1.90 0.554 704 1,647 2,824 4,921 ED+ 2 1,325 0.51 676 3.19 0.183 242 956 3,077 4,625 ED+ 3 1,480 0.83 1,228 1.76 0.143 212 460 2,931 4,541 P ( female)

Ht 155 cm Age 45 Short sleeves, cropped pants, cloth gloves 96.4 ED+ 4 1,410 0.82 1,160 1.86 0.176 248 570 2,978 4,588 TOTAL POST EXPOSURE PHOSMET FOR WORKER P 6,843 ED 6 3,296 783 ED 5 1,225 1.00 1,225 1.22 ND ND ND 3,427 4,982 ED 3 3,260 3,380 ED 2 760 1.12 851 1.75 ND ND ND 3,218 3,276 ED 0 990 0.98 972 1.54 0.363 359 682 3,352 4,712 ED+ 1 1,000 0.81 810 1.84 0.179 179 407 3,466 5,211 ED+ 2 1,043 1.11 1,159 1.29 0.075 78 124 3,448 5,037 ED+ 3 990 0.96 953 1.57 0.049 49 94 3,433 4,773 Q ( male)

Ht 168 cm Age 38 Long sleeve shirt, cap,

jeans, work boots 70 ED+ 4 1,070 0.98 1,052 1.42 0.12 128 225 3,277 5,051 TOTAL POST EXPOSURE PHOSMET FOR WORKER Q 1,532 32 TABLE 10. Summary of Postapplication Biomonitoring Data   Phosmet Treated Peach Trees Worker ID Clothing Body Weight kg Day of Collectiona 24 hour Urine Volumeb mL/ day Cnc mg/ mL Cn mg/ day Adjustment Factord SO residuee ug/ mL SO residuef ug/ day Reported Phosmet equivalentg ( ug/ day) Plasma ChE Activity ( U/ L) RBC ChE Activity ( U/ L)

ED 6 3,368 4,610 ED 5 1,150 1.70 1,955 1.65 ND ND ND 3,469 5,163 ED 3 3,424 2,774 ED 2 670 2.28 1,528 2.11 ND ND ND 3,520 4,839 ED 0 1,065 1.76 1,870 1.72 0.37 394 837 2,794 5,078 ED+ 1 1,075 1.70 1,824 1.76 0.18 194 421 3,434 4,625 ED+ 2 1,050 1.29 1,351 2.38 0.144 151 445 3,380 4,865 ED+ 3 1,350 1.34 1,808 1.78 0.062 84 184 3,514 4,367 R ( male)

Ht 170 cm Age 40 Long sleeves,

cap, jeans,

boots ( shirt cuffed up after 20 min work) 117.7 ED+ 4 660 1.84 1,214 2.65 0.178 117 384 3,421 5,483 TOTAL POST EXPOSURE PHOSMET FOR WORKER R 2,271 Note: The results for samples collected following re entry exposure are shaded in the table.

NS = no sample collected ND = Non detected a Date specimen collected in relation to exposure ( e. g., ED 6 represents the results on samples collected 6 days pre exposure, ED 0 represents the day of reentry)

b 24 hour urine volumes less than 800 mL are highlighted in bold.

c Cn ( mg/ mL) = urinary creatinine level d Adjustment Factor = Creatinine concentration was modeled as a function of a person's age, gender, and body surface area according to the formulas presented in Study Report.

Male µ g Cn/ day = 1.93( 140 age[ year]) * wt[ kg] 1.5* ht[ cm] 0.5 and Female µ g Cn/ day = 1.64( 140 age[ year]) * wt[ kg] 1.5* ht[ cm] 0.5 .

e SO ( ug/ mL) = daily concentration of sulfonyl metabolite measured in urine.

f SO ( ug/ day) = SO ( ug/ mL) * 24 hour urine volume.

g Reported Phosmet equivalents ( ug/ day) = corrected SO ( ug/ day) * adjustment factor * 1.235 molecular weight conversion to Phosmet equivalents. Molecular weight of phosmet = 317.33 and molecular weight of sulfonyl = 257. This value has been adjusted for possible incomplete urine collection   see footnote d. No pharmcokinetic factors have been utizilied in this calculation. 33 Table 11. Dislodgeable Foliar Residues of Phosmet and Phosmet Oxon Collection Day Phosmet ( ug/ cm2) Phosmet Oxon ( ug/ cm2) Average Phosmet ( ug/ cm2) Average Phosmet Oxon ( ug/ cm2)

0.006 0.0016 0.016 0.0016 0.013 0.0016 0.010 0.0016 ED  3 Pre Application 0.002 0.0000 0.01 0.001 6.7 0.012 6.6 0.011 5.5 0.011 5.4 0.012 5.6 0.012 ED  2 Day of Second Application 6.4 0.009 5.9 0.012 4.4 0.009 5.9 0.010 4.6 0.009 5.0 0.010 4.9 0.011 5.8 0.010 4.7 0.012 4.1 0.008 4.7 0.009 ED 0 Day of Exposure ( 2 days after second application)

4.8 0.009 5.0 0.010 3.8 0.010 3.5 0.008 3.3 0.008 3.6 0.008 ED + 1 ( 3 days after second application)

3.7 0.009 3.6 0.009 1.7 0.008 1.0 0.006 0.7 0.005 1.2 0.007 ED + 2 ( 4 days after second application)

1.4 0.006 1.2 0.006 1.0 0.005 1.3 0.009 0.6 0.004 0.9 0.007 ED + 3 ( 5 days after second application)

1.3 0.007 1.0 0.006 0.9 0.005 0.8 0.004 0.5 0.004 0.6 0.004 ED + 4 ( 6 days after second application)

0.9 0.005 0.7 0.004 Phosmet residues were corrected for an average field fortification of 83% Phosmet Oxon residues were corrected for an average field fortification of 91.7% 34 III DISCUSSION:

A. LIMITATIONS OF THE STUDY:

Major issues of concern in evaluation of the study include:

  Other than a molecular weight factor to account for the difference in molecular weight between the urinary metabolite sulfonyl, and the active ingredient phosmet, the Study Author did not factor any pharmacokinetic data into the estimation of phosmet equivalent dose. One factor typically considered in the estimate of dose is the percentage of active ingredient converted to urinary metabolite and subsequently excreted in the urine. Another factor to be considered is the percentage of metabolite expected to be excreted during the sampling time period. The Study Report protocol states that the sulfinyl and sulfonyl metabolites of phosmet account for approximately 50 60% of the administered radioactivity in urine in a rat oral metabolism study. The Authors did not take this into consideration in their estimate of dose.

  Many of the 24 hour urine collections demonstrate total volumes substantially below what is expected for normal, healthy adults. The volume of urine produced by a normal adult over a 24 hour period typically ranges between 800 and 1800 mL ( Tietz, 1970). Sample volumes obtained from the 16 workers against this standard demonstrate that 28 of 123 urine collections were below what normally would be expected.

  The Study Authors attempted to correct for incomplete urine collection. They adjusted sulfonyl concentration in the urine samples using a technique which compared measured creatinine to expected creatinine for each individual at each sampling event ( Mage et al., 2004). Based on this estimate of expected creatinine, an adjustment factor was applied to the sulfonyl concentration in each urine collection. Use of this correction strategy resulted in adjustment factors ranging from 0.64 to 4.38. Use of factors of these magnitudes indicate that in some instances, urine volume was as low as 25% of the expected volume.

  The study Authors also applied the adjustment factor to those samples where the actual creatinine level was higher than the expected creatinine level ( e. g., adjustment factor < 1.0). This had the effect of reducing the sulfonyl/ sulfinyl that was actually excreted by those individuals.

  The DFR analysis was most likely compromised by an exposure day rainfall event. The Study Report states that the " continued hard rain at the end of the exposure day had affected the dissipation kinetics and that a meaningful dissipation curve could not be developed." The study authors report that residue levels on the first and second day after the second application ( approximately 6 and 5 ug/ cm2, respectively) were consistent with expected DFR values. When comparing the DFR results with previously conducted phosmet dissipation regression curves, it appears that residues levels determined after the rain event demonstrate significantly lower levels than those expected.

  In the afternoon of the reentry day, postapplication activities were cut short due to heavy rain. The affect of this event on the phosmet exposure estimate is unknown. It is possible, however, that meaningful exposure was affected. The rainfall could have washed the transferable residue from the leaves, and/ or washed residue from the workers' skin and clothing. Or it is possible that the rain would solubilize the DFRs making them more readily available for transfer, or the water mass could have pushed residues through the clothing to skin increasing dermal exposure, or the damp clothing could hydrate the skin, possibly enhancing dermal absorption.

  Urinary field fortification levels were inconsistent, with seven samples, or 25%, demonstrating recovery values less than 50%. The Study Author deleted these values from the calculation of average recovery, reporting that the values must have been misfortified. If these fortification values were included in the calculations, overall recovery would be 84%, necessitating the use of a correction factor.

  The clothing worn by the workers was inconsistent. It is difficult to accurately characterize exposure in these circumstances. Table 1 outlines the clothing worn by the individual workers. A few of the workers wore 35 jackets for part of the workday, some of the workers wore gloves, some wore hats, some workers wore shortsleeved shirts and others wore long sleeved shirts.

  Several of the urine samples demonstrate incomplete oxidation of sulfinyl metabolite to the quantified metabolite, sulfonyl. The phosmet equivalent levels are based on measurement of sulfonyl only. The Study Authors did not adjust the estimate of phosmet concentration to account for this.

  EPA Reg No. 10163 169 specifies a maximum use rate of 4.25 lbs. ai/ A. The test substance was applied to the peach trees at a rate of 3 lbs. ai/ A.

  Postapplication activities were cut short ( i. e., the workers worked 6.5 hours on the day of exposure) due to the rainfall.

  Creatinine levels were determined; however, it was not reported if the specific gravity of the urine was analyzed.

  It is not well established that washed red cells can be frozen for a period of approximately one month and then assayed for RChe activity, as was the case in this Study. The laboratory utilized by the Study Author reports that their RChe method was validated using fresh specimens ( within 48 hours of collection) for estimation of RChe activity. The analytical lab utilized for cholinesterase testing does not have data to support whether or not frozen storage would affect stability.

  This study was conducted at only one test site, a peach orchard in Morven, Georgia. Therefore, DFR data was not collected from at least three geographically distinct locations for each formulation and crop type as specified in the guidelines. 36 _________________________ ____________________________ Name: Name: Evaluator Peer Reviewer Occupational Exposure Assessment Section Occupational Exposure Assessment Section __________________ ____________________ Date Date _________________________ Name: Head, Occupational Exposure Assessment Section _________________________ Date 37 APPENDIX A Compliance Checklists for " Biomonitoring of Workers Hand thinning Peaches Treated with Phosmet Insecticide" 38 COMPLIANCE CHECKLIST Compliance with OPPTS Series 875, Postapplication Occupational and Residential Exposure Test Guidelines, Group B: Guidelines, 875.2600 ( Biological monitoring) is critical. The itemized checklist below describes compliance with the major technical aspects of OPPTS 875.2600.

875.2600:

  The Agency requires investigators to submit protocols for review purposes prior to the inception of the study. Adequate pharmacokinetic data must exist to effectively interpret the data. This criterion was met.

  Expected deviations from GLPs should be presented concurrently with any protocol deviations and their potential study impacts. This criterion was met.

  The test substance should be a typical end use product of the active ingredient. This criterion was met.

  The application rate used in the study should be provided and should be the maximum rate specified on the label. However, monitoring following application at a typical application rate may be more appropriate in certain cases. This criterion was not met. The label states the maximum use rate is 4.25 lbs. ai/ acre. The test substance was applied to the peach trees at a rate of 3 lbs. ai/ acre.

  Selected sites and seasonal timing of monitoring should be appropriate to the activity. This criterion was met.

  A sufficient number of replicates should be generated to address the exposure issues associated with the population of interest. Specifically, each study should include a minimum of 15 individuals ( replicates) per activity. This criterion was met.

  Test subjects should be regular workers, volunteers trained in the work activities required, or typical homeowners. This criterion was met.

  The monitored activity should be representative of a typical working day for the specific task in order to capture all related exposure activities. This criterion may not have been met. Meaningful exposure was possibly affected by rainfall on the day the thinning tasks were conducted. In the afternoon of the reentry day, postapplication activities were cut short due to a significant rain event.

  The exposure monitoring period should be of sufficient length to ensure reasonable detectability of residues in biological media ( e. g., blood and urine) consistent with pharmacokinetic data such as excretion profile, duration time, etc. This criterion was met.

  Biomonitoring should be conducted using methodologies based on the pharmacokinetic properties of the pesticide ( parent compound and its metabolites) of concern ( e. g., need validated pharmacokinetic models from humans or appropriate animal surrogate and appropriate route of exposure). This criterion was not met. The study author did not account for the pharmacokinetics of the metabolite when estimating phosmet equivalents.

  Any protective clothing worn by study participants should be identified and should be consistent with the product label. This criterion was partially met. The clothing worn by the participants was identified; however, the test subjects wore their own clothing on the day of reentry, resulting in inconsistent work apparel. It is difficult to accurately characterize exposure in these circumstances. 39   If urine monitoring is being conducted, urine samples should be collected one or two days before participating in the applicator exposure monitoring activities and should continue on the day of exposure and for an appropriate time period after these activities have been completed, depending on the excretion kinetics of the compound. The 24 hour sample collection cycle should begin with the first void after beginning work activities and end with the first void on the following morning, continuing this 24 hour cycle on subsequent days. This criterion was not met. It appears that the urine sample collections were incomplete. 28 of 123 urine collections were below what normally would be expected in a normal healthy adult.

  If blood monitoring is being conducted, baseline blood samples should be collected from each individual prior to exposure. Based on pharmacokinetics, postapplication exposure samples should be collected at the appropriate times before, during, and after exposure. This criterion was met.

  Materials used for sample collection should not interfere with ( e. g., absorb) the analytes of interest. This criterion was met.

  Creatinine levels should be determined as a way of qualitatively monitoring completeness of urine collection samples. Specific gravity, as another measure of 24 hour sample completeness, should be performed as soon after collection as possible ( and before sample storage). These criteria were partially met. Creatinine levels were determined; however, it was not reported if the specific gravity of the urine was analyzed.

  Prior exposures to the test pesticide or structurally related compounds may interfere with study results. A brief history should be taken from each participant relating to known prior exposures to pesticides for at least the last 2 weeks, including reentry into potentially treated fields. For urine monitoring, there should also be a sufficient time period between such exposures and participation in the study to ensure adequate urinary clearance of the compound and its metabolites, based on pharmacokinetic data. This criterion was met.

  Validated analytical methods for the biological analyte ( parent compound and its metabolites) of sufficient sensitivity are needed. Information on method efficiency and limit of quantitation ( LOQ) should be provided. This criterion was met.

  Samples should be stored in a manner that will minimize deterioration and loss of analytes between collection and analysis. Biological monitoring samples ( e. g., serum, plasma and urine) should be refrigerated or stored frozen prior to analysis. Whole blood should not be frozen. Information on storage stability should be provided. This criterion was met. The red blood cells were washed with saline prior to frozen storage. It is expected that lysis of the red blood cells due to freezing would not interfere with the red blood cell cholinesterase testing.

  Data should be corrected if any appropriate field fortified, laboratory fortified or storage stability recovery is less than 90 percent. This criterion was not met. Overall average recovery of all field fortification samples was 84%; however, the study author excluded seven of the samples they considered to be misfortified with recovery values < 50%. This resulted in an overall average recovery of 103%.

  Unless stability of the analyte has been established prior to initiation of the study, three samples of control ( nonparticipant) should be fortified with two levels of the biological analyte ( parent or metabolite( s), whichever is appropriate) for each experimental site. . This criterion was met.

  Each subject's absorbed dose should be expressed in terms of body weight using his/ her own measured value, and as a cumulative total for each exposure period. The arithmetic mean, range, standard deviation, and coefficient of variation should be calculated from the results of all 40 individuals. Geometric mean, range and standard deviation may be calculated if the results are shown to be log normally distributed. Other distributional data should be reported, to the extent possible ( e. g., percentiles). These criteria were partially met. 41 COMPLIANCE CHECKLIST Compliance with OPPTS Series 875, Postapplication Occupational and Residential Exposure Test Guidelines, Group B: Guidelines, 875.2100 ( dislodgeable foliar residue dissipation  postapplication) is critical. The itemized checklist below describes compliance with the major technical aspects of OPPTS 875.2100.

875.2100:

  The test substance must be the typical end use product of the active ingredient. This criterion was met.

  The production of metabolites, breakdown products, or the presence of contaminants of potential toxicologic concern, should be considered on a case by case basis. This criterion was partially met. The Study assayed for both phosmet and phosmet oxon, however, no explanation was provided for other possible breakdown products.   Applications should occur at the time of season that the end use product is normally applied to achieve intended pest control. This criterion was met.

  Initiating testing immediately before a precipitation event should be avoided. This criterion was partially met. The Study Authors reported that " examination of the post exposure DFR results let us to conclude that the continuing hard rain at the end of the exposure day had affected the dissipation kinetics".

  The end use product should be applied by the application method recommended for the crop. Information that verifies that the application equipment ( e. g., sprayer) was properly calibrated should be included. This criteria was met. The application equipment was calibrated and airblast application is the recommended treatment for peach trees.

  The application rate used in the study should be provided and should be the maximum rate specified on the label. However, monitoring following application at a typical application rate is more appropriate in certain cases. This criterion was not met. The label states the maximum use rate is 3.75 lbs. ai/ acre. The test substance was applied to the peach trees at a rate of 3 lbs. ai/ acre.

  If multiple applications are made, the minimum allowable interval between applications should be used. This criterion was met.

  Dislodgeable foliar residue ( DFR) data should be collected from at least three geographically distinct locations for each formulation and crop type. The sites should be representative of the regions ( and crops) where the chemical is used. This criterion was not met. This study was conducted at only one test site, a peach orchard in Morven, Georgia.

  The site( s) treated should be representative of reasonable worst case climatic conditions expected in intended use areas. Meteorological conditions including temperature, wind speed, daily rainfall, and humidity should be provided for the duration of the study. This criterion was met.

  Sampling should be sufficient to characterize the dissipation mechanisms of the compound ( e. g., three half lives or 35 days after the final application, unless the compound has been found to fully dissipate in less time; for more persistent pesticides, longer sampling periods may be necessary). Sampling intervals may be relatively short in the beginning and lengthen as the study progresses. Background samples should be collected before application of the test substance occurs. This criteria was not met, however, the purpose of collection DFR residue for this study was to characterize the residue level on the day of reentry, The DFR data was not intended to be used to establish a dissipation curve". 42   Triplicate, randomly collected samples should be collected at each sampling interval. This criterion was met.

  A leaf punch apparatus should be used unless the nature of the crop precludes its use. Samples should represent at least an area of 400 cm2. This criterion was met.

  Control plots should be established from which sufficient control samples can be collected. Control sites should be upwind and a reasonable distance from the treatment site. This criterion may have been met. The study author reported that additional nontreated control samples were collected from nontreated orchards; however, the location of this orchard was not specified in the report and the collected residues were not assayed..

  Residues should be dislodged from leaf surfaces using an aqueous surfactant solution within a reasonable time period ( i. e., EPA recommends that dislodging occur within 4 hours). Dislodging should be repeated at least once and the resultant solutions pooled for analysis. This criterion was met.

  Samples should be stored in a manner that will minimize deterioration and loss of analytes between collection and analysis. Information on storage stability should be provided. This criterion was met.

  Validated analytical methods of sufficient sensitivity are needed. Information on method efficiency ( residue recovery), and limit of quantitation ( LOQ) should be provided. This criterion was met.

  Information on recovery samples must be included in the study report. A complete set of field recoveries should consist of at least one blank control sample and three or more each of a lowlevel and high level fortification. These fortifications should be in the range of anticipated residue levels in the field study. This criterion was met.

  Raw residue data must be corrected if appropriate recovery values are less than 90 percent). This criteria was met.

  Dislodgeable foliar residues should be reported as mg or µ g per m2 or cm2 of leaf sampled. Distributional data should be reported, to the extent possible. This criterion was met. 43 REFERENCES Mage, David T., Allen, R. H., Gondy, G, Smith, W., Barr, D. B., and L. Needham. Estimating pesticide dose from urinary pesticide concentration data by creatinine correction in the Third National Health and Nutrition Examination Survey ( NHANES III). ( 2004). JEAEE14: 457 465.

Tietz, Norbert W. ed. ( 1970). Fundamentals of Clinical Chemistry, Philadelphia, PA: W. B. Saunders Company. ISBN 0 7216 8865 9.