T able 28. Avian Acute and Chronic Risk Quotients for Single Application of Dichlorvos to Turf ( Dietary based RQs based on Pheasant LC50 of 568 ppm and Mallard NOAEC of 5 ppm). 43 Site/ App. Method App. Rate ( lbs ai/ A) Food Items Acute RQ ( EEC/ LC50) Chronic RQ ( EEC/ NOAEC )

Turf/ Spray/ 1 app 0.2 Short grass 0.03 3.86****

Tall grass 0.02 1.77****

Broadleaf plants/ Small Insects 0.02 2.17****

Fruits/ Pods/ Large Insects 0.00 0.24 * exceeds endangered species LOC ( LOC = 0.1) ** exceeds endangered species and acute restricted use LOC ( LOC = 0.2) *** exceeds endangered species, restricted use and acute risk LOC ( LOC = 0.5) **** exceeds chronic LOC ( LOC = 1)

An analysis of the results for four applications of dichlorvos to turf at the maximum application rate of 0.2 lb ai/ A, no avian acute LOC is exceeded ( Table 29). The avian chronic level of concern is exceeded for birds that consume short grass, tall grass, and broadleaf plants/ small insects.

Table 29. Avian Acute and Chronic Risk Quotients for Four Applications of Dichlorvos to Turf ( Dietary based RQs based on Pheasant LC50 of 568 ppm and Mallard NOAEC of 5 ppm).

Site/ App. Method App. Rate ( lbs ai/ A) Food Items Acute RQ ( EEC/ LC50) Chronic RQ ( EEC/ NOAEC )

Turf/ Spray/ 4 app with 30 day application interval 0.2 Short grass 0.03 3.86****

Tall grass 0.02 1.77****

Broadleaf plants/ Small Insects 0.02 2.17****

Fruits/ Pods/ Large Insects 0.00 0.24 * exceeds endangered species LOC ( LOC = 0.1) ** exceeds endangered species and acute restricted use LOC ( LOC = 0.2) *** exceeds endangered species, restricted use and acute risk LOC ( LOC = 0.5) **** exceeds chronic LOC ( LOC = 1)

Flying Insect Scenario An analysis of the results for 75 applications of dichlorvos for flying insect control at the maximum application rate of 0.2 lb ai/ A, no avian acute LOC is exceeded ( Table 30). The avian chronic level of concern is exceeded for birds that consume short grass, tall grass, and broadleaf plants/ small insects. 44 Table 30. Avian Acute and Chronic Risk Quotients for 75 Applications of Dichlorvos for Flying Insect Control ( Dietary based RQs based on Pheasant LC50 of 568 ppm and Mallard NOAEC of 5 ppm).

Site/ App. Method App. Rate ( lbs ai/ A) Food Items Acute RQ ( EEC/ LC50) Chronic RQ ( EEC/ NOAEC )

Flying Insects/ Spray / 75 app with 5 day application interval 0.2 Short grass 0.03 3.86****

Tall grass 0.02 1.77****

Broadleaf plants/ Small Insects 0.02 2.17****

Fruits/ Pods/ Large Insects 0.00 0.24 * exceeds endangered species LOC ( LOC = 0.1) ** exceeds endangered species and acute restricted use LOC ( LOC = 0.2) *** exceeds endangered species, restricted use and acute risk LOC ( LOC = 0.5) **** exceeds chronic LOC ( LOC = 1)

ii. Mammals Turf Scenarios An analysis of the results for a single broadcast application of dichlorvos to turf at the maximum application rate of 0.2 lb ai/ A, the mammalian endangered species LOC is exceeded for the 15 g and 35 g mammals that consumes short grass( Table 31). The mammalian chronic level of concern is exceeded for 15 g, 35 g, and 1000 g mammals that consume short grass, tall grass, and broadleaf plants/ small insects.

T able 31. Mammalian Acute and Chronic Risk Quotients for Single Application of Dichlorvos to Turf ( Dose based RQs based on Rat LD50 of 56 mg/ kg and Rat NOAEC of 5 ppm).

15 g mammal 35 g mammal 1000 g mammal Acute RQ Chronic RQ Acute RQ Chronic RQ Acute RQ Chronic RQ Short grass 0.15* 8.34**** 0.13* 7.16**** 0.07 3.76****

Tall grass 0.07 3.82**** 0.06 3.28**** 0.03 1.72****

Broadleaf plants/ Small Insects 0.08 4.69**** 0.07 4.03**** 0.04 2.12****

Fruits/ Pods/ Large Insects 0.01 0.52 0.01 0.45 0.00 0.24 45 Seeds ( granivore) 0.00 0.12 0.00 0.10 0.00 0.05 * exceeds endangered species LOC ( LOC = 0.1) ** exceeds endangered species and acute restricted use LOC ( LOC = 0.2) *** exceeds endangered species, restricted use and acute risk LOC ( LOC = 0.5) **** exceeds chronic LOC ( LOC = 1)

An analysis of the results for four broadcast application of dichlorvos to turf at the maximum application rate of 0.2 lb ai/ A, the mammalian endangered species LOC is exceeded for the 15 g and 35 g mammals that consume short grass( Table 32). The mammalian chronic level of concern is exceeded for 15 g, 35 g, and 1000 g mammals that consume short grass, tall grass, and broadleaf plants/ small insects.

Table 32. Mammalian Acute and Chronic Risk Quotients for Four Applications of Dichlorvos to Turf ( Dose based RQs based on Rat LD50 of 56 mg/ kg and Rat NOAEC of 5 ppm).

15 g mammal 35 g mammal 1000 g mammal Acute RQ Chronic RQ Acute RQ Chronic RQ Acute RQ Chronic RQ Short grass 0.15* 8.34**** 0.13* 7.16**** 0.07 3.76***

Tall grass 0.07 3.82**** 0.06 3.28**** 0.03 1.72***

Broadleaf plants/ Small Insects 0.08 4.69**** 0.07 4.03**** 0.04 2.12***

Fruits/ Pods/ Large Insects 0.01 0.52 0.01 0.45 0.00 0.24 Seeds ( granivore) 0.00 0.12 0.00 0.10 0.00 0.05 * exceeds endangered species LOC ( LOC = 0.1) ** exceeds endangered species and acute restricted use LOC ( LOC = 0.2) *** exceeds endangered species, restricted use and acute risk LOC ( LOC = 0.5) **** exceeds chronic LOC ( LOC = 1)

Flying Insect Scenario An analysis of the results for 75 applications of dichlorvos for flying insect control at the maximum application rate of 0.2 lb ai/ A, the mammalian endangered species LOC is exceeded for 15 g and 35 mammals consuming short grass ( Table 33). The mammalian chronic level of concern is exceeded for mammals ( 15 g, 35 g, 1000 g) that consume short grass, tall grass, and broadleaf plants/ small insects.

Table 33. Mammalian Acute and Chronic Risk Quotients for 75 Applications of Dichlorvos for Flying Insect Control ( Dose based RQs based on Rat LD50 of 56 mg/ kg and Rat NOAEC of 5 ppm).

15 g mammal 35 g mammal 1000 g mammal Acute RQ Chronic RQ Acute RQ Chronic RQ Acute RQ Chronic RQ 46 Short grass 0.15* 8.34**** 0.13* 7.16**** 0.07 3.76****

Tall grass 0.07 3.82**** 0.06 3.28**** 0.03 1.72****

Broadleaf plants/ Small Insects 0.08 4.69**** 0.07 4.03**** 0.04 2.12****

Fruits/ Pods/ Large Insects 0.01 0.52 0.01 0.45 0.00 0.24 Seeds ( granivore) 0.00 0.12 0.00 0.10 0.00 0.05 * exceeds endangered species LOC ( LOC = 0.1) ** exceeds endangered species and acute restricted use LOC ( LOC = 0.2) *** exceeds endangered species, restricted use and acute risk LOC ( LOC = 0.5) **** exceeds chronic LOC ( LOC = 1)

3 Non target Terrestrial Invertebrates Honeybee acute contact toxicity values indicate that dichlorvos is highly toxic to this insect species. Toxicity tests using residues on foliage indicate dichlorvos is practically non toxic to honey bees.

The overall acute risk to honeybees and other non target and beneficial insects is expected to be very high for applications of liquid products at 0.2 lb ai/ a. Since dichlorvos is very highly toxic to bees ( LD50)= 0.495 µ g/ bee, it is expected that bees, as well as other non target and beneficial insects, could be harmed if exposed to dichlorvos during treatment.

4. Non target Terrestrial and Aquatic Plants As described in the analysis section, there were no registrant submitted terrestrial plant studies so risk to terrestrial plants can not be assessed.

There are supplemental aquatic plant studies that can be used descriptively to discuss potential risk to aquatic plants. The 48 hour EC50 values of > 100000 ppb for green algae, 14000 ppb for algae ( the species were not given) and 17000 28000 ppb for marine diatom are reported by Mayer et al. 1986. The modeled peak EEC value for turf is 2.33 ppb. Comparisons of the toxicities and the aquatic EEC values indicate minimal aquatic plant risk.

5. Non target Terrestrial Animals  Bait Formulations An acute risk assessment for bait formulations was performed for dichlorvos outdoor use around animal premises. Birds and mammals may be exposed to the bait by ingesting granules. The number of lethal doses ( LD50' s) that are available within one square foot immediately after application can be used as a risk quotient ( LD50' s/ ft 2) for the exposure to bait pesticides. Chronic risk assessments are not performed for bait products.

The acute risk quotients for birds and mammals are tabulated in Table 34. The results indicate that for applications of bait products applied at the maximum rate of 0.0025 lb/ 1000 ft 2 , the acute avian RQs exceed endangered species, restricted use and acute risk LOCs for 20 g birds. The endangered species LOC is exceeded for 100 g birds. 47 Granular bait can be applied up to 120 applications ( worse case scenario) with 3 day application interval. However, for the bait application, dichlorvos can only be applied to animal premise areas ( soil, near buildings) and not applied directly to grass and turf. When evaluating the aerobic soil half life of 0.42 days, it becomes clear that in a 3 day application interval, the original 0.1 lbs/ A of dichlorvos would have gone through approximately 7 half life cycles, leaving only approximately 0.0008 lbs/ A of the original parent product. Therefore, we assume that the risk quotients calculated for 1 application at 0.1 lbs/ A approximate the risk quotients for 120 applications with 3 day application interval.

Table 34. Avian and Mammalian Acute Risk Quotients for 1 application of Bait Products ( based on a Mallard LD50 of 7.78 mg ai/ kg and Rat LD50 of 56 mg/ kg).

Granular Bait ( 1 application at 0.1 lbs/ A) Acute RQ ( LD50/ ft 2 )

Avian 20 g bird 0.959***

100 g bird 0.151*

1000 g bird 0.011 Mammals 15 g mammal 0.042 35 g mammal 0.022 1000 g mammal 0.002 * exceeds endangered species LOC ( LOC = 0.1) ** exceeds endangered species and acute restricted use LOC ( LOC = 0.2) *** exceeds endangered species, restricted use and acute risk LOC ( LOC = 0.5)

B. Risk Description  Interpretation of Direct Effects 1. Risks to Aquatic Animals Summary of Major Conclusions Acceptable data on dichlorvos indicates it is very highly toxic to freshwater fish ( LC50 = 183 ppb for most sensitive species), moderately toxic to estuarine/ marine fish ( EC50 = 7350 ppb for the one species tested), very highly toxic to freshwater invertebrates ( LC50 = 0.28 ppb for most sensitive species) and very highly toxic to estuarine invertebrates ( LC50 = 19.1 ppb for most sensitive species). Chronic studies established NOAEL values of 5.2 ppb ( rainbow trout), 960 ppb ( sheepshead minnow), 0.0058 ppb ( daphnid) and 1.48 ppb ( mysid shrimp).

There is acute risk for freshwater invertebrates with RQs of 1.6 ( FL turf) and 1.6 ( PA turf) for one spray application. For 4 applications, the RQs are 2.41 ( FL turf) and 2.1 ( PA turf). These RQs exceeds the endangered species, restricted use, and acute risk LOC. In addition, the chronic level of concern is exceeded for freshwater invertebrates [ egg production and growth 48 ( length and weight) endpoint] for all of the turf scenarios ( one and four applications). Based on these findings, there is a potential for acute and chronic risk to freshwater invertebrates from applications to turf.

For flying insect ( including adult mosquitoes) use, EFED is unable to assess risk quantitatively. It may be assumed that the exposure to dichlorvos from flying insect use would be less than that expected from turf use. However, the potential risk to freshwater and marine/ estuarine invertebrates can not be quantified and therefore can not be assessed nor discounted.

Exposure to aquatic animals from bait formulations applied around animal premises is expected to be minimal because treatment sites are small and localized. Therefore, the bait formulation scenario for aquatic animals was not addressed in this risk assessment.

2. Risks to Terrestrial Animals Summary of Major Conclusions Based on the results of acceptable ecotoxicity studies, dichlorvos is very highly toxic to birds on an acute oral basis ( LD50= 7.8 mg/ kg for most sensitive species), moderately toxic to birds on a subacute dietary basis ( LC50 = 568 ppm for most sensitive species) and moderately toxic to mammals on an acute oral basis ( LD50 = 56 80 mg/ kg). Chronic toxicity studies established NOAEL values of 5 ppm ( mallard), 20 ppm ( rat) and 30 ppm ( bobwhite).

The chronic risk endangered species LOCs are exceeded on turf applications ( both 1 and 4 applications) for birds that consume short grass, tall grass, and broadleaf plants/ small insects ( with RQs ranging from 1.77 to 3.86). For the flying insect scenario, no acute LOCs are exceeded. Chronic LOCs are exceeded for birds that consume short grass, tall grass, and broadleaf plants/ small insects.

For mammals, for both the 1 and 4 applications of dichlorvos to turf, the chronic LOC is exceeded for 15 g, 35 g, and 1000 g mammals that consume short grass, tall grass, and broadleaf plants/ small insects. For turf application, there are acute endangered species LOC exceedences for the 15 g and 35 g mammals that consumes short grass.

The acute risk, acute restricted use, and acute endangered species LOCs for a small bird ( 20 g weight) are exceeded for the bait formulation scenario ( Acute RQ = 0.959). The endangered species OC is exceeded for the 100 g mammals with the bait scenario. Chronic risk to birds from the bait formulation can not be assessed at this time.

There is a possibility of risk to birds and small mammals from ingestion of the bait product. Dichlorvos is highly toxic to birds on an acute oral basis ( LD50 < 10 mg/ kg). The bait products appear to be of granular consistency and sugar based ( e. g., front panel of product label for EPA Reg. No. 769 568 states FLY Bait Sugar Base With DDVP). Bait product labels carry directions for use both as a dry bait ( sprinkle lightly where flies congregate) and wet bait ( dissolve in water). Wet baits pose a minimal risk to terrestrial animals. Avian reproduction laboratory studies found that it is difficult to keep the material in the feed for a 24 hour period. Bait products of similar granular consistency also might have a very short life in the field. Some of the labels bear directions to reapply every 3 to 5 days until control is achieved. 49 C. Threatened and Endangered Species Concerns 1. Taxonomic Groups Potentially at Risk The Agency's levels of concern for endangered and threatened freshwater invertebrates, birds, and mammals are exceeded for dichlorvos use. A summary of the endangered species taxonomic groups potentially at risk from dichlorvos use are listed in Table 35. Because turf , flying insect, and bait formulation use are available in all states, the endangered species listing encompasses all dichlorvos use areas..

The preliminary risk assessment for endangered species indicates that dichlorvos exceeds the endangered species LOCs for the following combinations of analyzed uses and species:

· Freshwater invertebrates ( acute): use on turf ( 1 application and 4 applications, both FL and PA scenarios)

· Freshwater invertebrates ( chronic): use on turf ( 1 application and 4 applications, both FL and PA scenarios)

· Birds ( chronic): use on turf ( 1 application and 4 applications) for birds consuming short grass, tall grass, and broadleaf plants/ small insects · Birds ( chronic): use as flying insect control for birds consuming short grass, tall grass, and broadleaf plants/ small insects · Birds ( acute): use as bait formulation for 20 g and 100g bird · Mammals ( acute): use on turf ( 1 application and 4 applications) 15 g and 35 g mammals that consumes short grass.

· Mammals ( chronic): use on turf ( 1 application and 4 applications) 15 g, 35 g, and 1000 g mammals that consume short grass, tall grass, and broadleaf plants/ small insects.

Table 35. Tabulation by taxonomic group and total states of listed species that occur in dichlorvos use areas Taxonomic Group Bir ds Mam mals Rep tiles Am phi bia ns Fish Cr us tac ea ns Ar ac hn id s Inse cts Sn ail s Cl a m s Plant s Total Unique Species 57 61 28 19 113 20 12 44 30 70 548 50 Total States 49 47 19 12 40 12 4 27 15 28 49 The Agency has developed the Endangered Species Protection Program to identify pesticides whose use may cause adverse impacts on endangered and threatened species, and to implement mitigation measures that address these impacts. The Endangered Species Act requires federal agencies to ensure that their actions are not likely to jeopardize listed species or adversely modify designated critical habitat. To analyze the potential of registered pesticide uses to affect any particular species, EPA puts basic toxicity and exposure data developed for REDs into context for individual listed species and their locations by evaluating important ecological parameters, pesticide use information, the geographic relationship between specific pesticide uses and species locations, and biological requirements and behavioral aspects of the particular species. This analysis will take into consideration any regulatory changes recommended in this RED that are being implemented at this time. A determination that there is a likelihood of potential impact to a listed species may result in limitations on use of the pesticide, other measures to mitigate any potential impact, or consultations with the Fish and Wildlife Service and/ or the National Marine Fisheries Service as necessary.

The Endangered Species Protection Program as described in a Federal Register notice ( 54 FR 27984 28008, July 3, 1989) is currently being implemented on an interim basis. As part of the interim program, the Agency has developed County Specific Pamphlets that articulate many of the specific measures outlined in the Biological Opinions issued to date. The Pamphlets are available for voluntary use by pesticide applicators on EPA's website at www. epa. gov/ espp. A final Endangered Species Protection Program, which may be altered from the interim program, was proposed for public comment in the Federal Register December 2, 2002.

2 . Probit Slope Analysis The probit slope response relationship is evaluated to calculate the change of an individual event corresponding to the listed species acute LOCs. If information is unavailable to estimate a slope for a particular study, a default slope assumption of 4.5 is used as per original Agency assumptions of typical slope cited in Urban and Cook ( 1986).

Freshwater Invertebrates Raw data is not provided in the daphnid acute EC50 study ( MRID 40098001/ Mayer and Ellersieck 1986) to calculate a slope. RQ exceedances occur for freshwater invertebrate species for the turf scenario ( 1 application and 4 applications). Based on the default slope assumption of 4.5, the individual mortality associated with the minimum and maximum calculated RQ value ( 6.71 and 33.29) result in an estimated chance of individual mortality of 1 in 1 ( 100 %). The corresponding estimated chance of individual mortality associated with the listed species LOC of 0.05 is 1 in 4.17E+ 08.

Birds Raw data is not provided in the mallard duck acute LD50 study ( MRID 00160000/ Hudson et al. 1984) to calculate a slope. RQ exceedances occur for bird species for the flying insect and bait formulation scenario. Based on the default slope assumption of 4.5, the individual mortality associated with the calculated minimum and maximum RQ value ( 0.17 and 0.36) for flying insect scenario result in an estimated chance of individual mortality of 1 in 3.74E+ 03 to 1 in 4.36E+ 01 . For the bait scenario, RQ range of 0.151 to 0.959, result in an estimated chance of individual mortality of 1 in 9.08E+ 03 to 1 in 2.14 ( 50%). The corresponding estimated chance of individual mortality associated with the listed species LOC of 0.1 is 1 in 2.94 E+ 05. 51 Mammals Raw data is not provided in the rat acute LD 50 study ( MRID 0005467) to calculate a slope. Therefore, the event probability was calculated for mammalian LOC based on a default slope of 4.5. RQ exceedances occur for mammalian species for the turf and flying insect scenario. The individual mortality associated with the calculated RQ values ( 0.13 and 0.26) for turf scenario result in an estimated chance of individual mortality of 1 in 2.99E+ 04 and 1 in 2.36E+ 02, respectively. For the flying insect scenario, RQ range of 0.33 to 1.58, result in an estimated chance of individual mortality of 1 in 6.61E+ 01 to 1 in 1.23E+ 0 ( 100%).

Based on an assumption of a probit dose response relationship with a mean estimated slope of 4.5, the corresponding estimated chance of individual mortality associated with the mammalian listed species LOC of 0.1 is 1 in 294,000.

It is recognized that extrapolation of very low probability events is associated with considerable uncertainty in the resulting estimates. To explore possible bounds to such estimates, the upper and lower values for the mean slope estimate can be used to calculate upper and lower estimates of the effects probability associated with the listed species LOC. However, since slope is based on a default assumption of 4.5, the 95 percent confidence intervals for the slopes are unavailable.

3. Critical Habitat In the evaluation of pesticide effects on designated critical habitat, consideration is given to the physical and biological features ( constituent elements) of a critical habitat identified by the FWS and NMFS as essential to the conservation of a listed species and which may require special management considerations or protection. The evaluation of impacts for a screening level pesticide risk assessment focuses on the biological features that are constituent elements and is accomplished using the screening level taxonomic analysis ( risk quotients, RQs) and listed species levels of concern ( LOCs) that are used to evaluate direct and indirect effects to listed organisms.

The screening level risk assessment has identified potential concerns for indirect effects on listed species for those organisms dependent upon freshwater invertebrates, birds, and mammals. In light of the potential for indirect effects, the next step for EPA, FWS, and the NMFS is to identify which listed species and critical habitat are potentially implicated.

Analytically, the identification of such species and critical habitat can occur in either of two ways. First, the agencies could determine whether the action area overlaps critical habitat or the occupied range of any listed species. If so, EPA would examine whether the pesticide's potential impacts on non endangered species would affect the listed species indirectly or directly affect a constituent element of the critical habitat. Alternatively, the agencies could determine which listed species depend on biological resources, or have constituent elements that fall into, the taxa that may be directly or indirectly impacted by the pesticide. Then EPA would determine whether use of the pesticide overlaps with the critical habitat or the occupied range of those listed species. At present, the information reviewed by EPA does not permit use of either analytical approach to make a definitive identification of species that are potentially impacted indirectly or critical habitats that are potentially impacted directly by the use of the pesticide. EPA and the Service( s) are working together to conduct the necessary analysis.

This screening level risk assessment for critical habitat provides a listing of potential biological features that, if the are constituent elements of one or more critical habitats, would be of potential concern. These correspond to the taxa identified above as being of potential concern for indirect effects and include the following: freshwater invertebrates, birds, and mammals. This list should serve as an initial step in problem formulation for further assessment of critical habitat impacts outlined above, should additional work be necessary.

4. Indirect Effect Analyses The Agency acknowledges that pesticides have the potential to exert indirect effects upon the listed organisms by, for example, perturbing forage or prey availability, altering the extent of nesting habitat, creating gaps in the food chain, etc. In conducting a screen for indirect effects, direct effect LOCs for each taxonomic group are used to make inferences concerning the potential for indirect effects upon listed species that rely upon non endangered organisms in these taxonomic groups as resources critical to their life cycle. 52 Because screening level acute RQs for freshwater invertebrates, birds, and mammals exceed the endangered species acute LOCs, the Agency uses the dose response relationship from the toxicity study used for calculating the RQ to estimate the probability of acute effects associated with an exposure equivalent to the EEC. This information serves as a guide to establish the need for and extent of additional analysis that may be performed using Services provided   species profiles  as well as evaluations of the geographical and temporal nature of the exposure to ascertain if a   not likely to adversely affect  determination can be made. The degree to which additional analyses are performed is commensurate with the predicted probability of adverse effects from the comparison of the dose response information with the EECs. The greater the probability that exposures will produce effects on a taxa, the greater the concern for potential indirect effects for listed species dependent upon that taxa, and therefore, the more intensive the analysis on the potential listed species of concern, their locations relative to the use site, and information regarding the use scenario ( e. g., timing, frequency, and geographical extent of pesticide application).

Screening level acute RQs for aquatic invertebrates, birds, and mammals are above the nonendangered species LOCs. The Agency considers this to be indicative of a potential for adverse effects to those listed species that rely either on a specific plant species ( plant species obligate) or multiple plant species ( plant dependent) for some important aspect of their life cycle. The Agency may determine if listed organisms for which plants are a critical component of their resource needs are within the pesticide use area. This is accomplished through a comparison of Service provided   species profiles  and listed species location data. If no listed organisms that are either plant species obligates or plant dependent reside within the pesticide use area, a no effect determination on listed species is made. If plant species obligate or dependent organism may reside within the pesticide use area, the Agency may consider temporal and geographical nature of exposure, and the scope of the effects data, to determine if any potential effects can be determined to not likely adversely affect a plant species obligate or dependent listed organism.

a. Aquatic Species Indirect effects to endangered/ threatened fish that depend on freshwater invertebrates as a primary source of food, as well as larger aquatic animals that rely on aquatic ( freshwater) invertebrate populations as a food source may be affected by the direct or chronic effects of dichlorvos use.

b. Terrestrial Species Although RQs were not calculated for terrestrial plants, due to dichlorvos' mode of action, use, and the lack of aquatic plant risk, this assessment concludes that plant dependent species will not be affected indirectly from dichlorvos use.

The Agency acknowledges that pesticides have the potential to exert indirect effects upon endangered or threatened species, by, for example, perturbing forage or prey availability, altering the extent of nesting habitat, etc. The screen for indirect effects includes using direct effect LOCs for non endangered species to infer the potential for indirect effects upon listed species that rely upon non endangered organisms as resources critical to their life cycle.

Because at intended use rates dichlorvos may cause mortality in exposed bird and mammal populations, there are potential concerns for indirect effects on those listed terrestrial organisms that are dependant upon vertebrate species ( birds, mammals, reptiles) as prey items. Additionally, indirect effects to endangered/ threatened fish, invertebrates, and mammals that depend on freshwater invertebrates as a primary source of food may occur. 53 The high acute toxicity of dichlorvos to honeybees may lead to mortality to this and other insectpollinators Listed plant species dependant upon insect pollination may be indirectly affected by the loss of all or part of such insect populations. Additionally, the potential risk to bird species from dichlorvos use could also affect bird pollinated plant species.

A potential drop in both vertebrate and invertebrate biomass associated with dichlorvos use may reduce a significant portion of the prey base. If this prey base is removed at a critical life cycle juncture, over a large area, or it if is removed for a long enough duration, some species may have difficulty meeting energy needs. Some species may be particularly sensitive during reproductive or developmental periods.

E. Description of Assumptions, Uncertainties, Strengths, and Limitations 1. Assumptions and Limitations Related to Exposure for all Taxa a. Maximum Use Scenario This screening level risk assessment relies on labeled statements of the maximum rate of dichlorvos application, the maximum number of applications, and the shortest interval between applications ( when applicable). Together, these assumptions constitute a maximum use scenario and can overestimate risk. However, the maximum use scenario must be considered because it is a reflection of the allowable use of dichlorvos.

2. Assumptions and Limitations Related to Exposure for Aquatic Species a. Lack of Averaging Time for Exposure For an acute risk assessment, there is no averaging time for exposure. An instantaneous peak concentration, with a 1 in 10 year return frequency, is assumed. The use of the instantaneous peak assumes that instantaneous exposure is of sufficient duration to elicit acute effects comparable to those observed over more protracted exposure periods tested in the laboratory, typically 48 to 96 hours. In the absence of data regarding time to toxic event analyses and latent responses to instantaneous exposure, the degree to which risk is overestimated cannot be quantified.

b. Routes of exposure Screening level risk assessments pesticide application for aquatic organisms consider exposure through the gills. Other potential routes of exposure, not considered in this assessment, are discussed below:

· Dietary consumption The screening assessment does not consider the ingestion pathway. This exposure may occur through ingestion of contaminated vegetation, invertebrates, or other exposed prey items.

· Dermal exposure The screening assessment does not consider dermal exposure. Dermal exposure may occur through one potential source: contact with contaminated water. The available measured data related to aquatic wildlife dermal contact with pesticides are extremely limited.

3. Assumptions and Limitations Related to Exposure for Terrestrial Species a. The LD50/ sq. ft. Index The LD50/ sq. ft. index was developed by Felthousen ( 1977). The concept was based upon field observations made by DeWitt ( 1966) who suggested that ecological effects are expected to occur when exposure residues that equal or exceed the LD50 value for a pesticide, as determined from laboratory studies, are reached in the field. The index was developed, in response to the Registration Divisions' request for guidance for classifying use patterns, involving granulated formulations, baits, and seed 54 treatments, for labeling purposes. At that time risk criteria considerations were typically based on the amount of residues likely to occur, immediately following application, in or on feed items likely to be consumed by non target wildlife species. In so much as granular formulations, baits and seed treatments leave very little residue in or on non target food items, a hazard index had to be developed to address theses routes of exposure. It's important to note that the LD50/ sq. ft. concept is an index to hazard that presumes exposure will occur on the treated areas ( a deterministic assessment) rather than a tool that attempts to quantify the temporal and spatial relationship of exposure ( i. e., a probabilistic assessment tool) to a non target organism.

The LD50/ sq. ft. index used to predict risk to non target wildlife species has been peer reviewed by numerous scientists, both within and outside of the Agency and, in general, has been accepted as a useful tool for addressing ecological hazard from the use of granulated formulations. In March of 1992, the Agency used this index in its " Comparative Analysis of Acute Avian Risk from Granular Pesticides" document. This document provided explanation, discussion and analysis of the index as well as specific examples of risk quotients derived from the index. In 1996 the FIFRA Science Advisory Panel ( SAP) reviewed and approved the environmental assessments derived from the index for those chemicals evaluated in the corn cluster document. The SAP even suggested that the acute risk indices calculated from the index may actually underestimate risk.

Based on this long history of scientific peer review, which has repeatedly supported the use of the LD50/ sq. ft. risk index in ecological hazard assessments, we believe that the index is appropriate for determining and classifying ecological risk to terrestrial wildlife from the use of bait formulations.

b. Uncertainties Associated with the LD50/ sq. ft. Index Risk quotients based on the LD50/ sq. ft. hazard index have been criticized as being too conservative and overestimating " real world" risk. It has been argued that the method greatly oversimplifies the exposure component to hazard assessment by not specifically addressing the temporal and spatial situations that non target wildlife species experience under field conditions. Although this is somewhat correct there are still many other exposure related and toxicological factors that are not accounted for by the index which may actually underestimate risk from this method.

For example, the LD50/ sq. ft. index is based solely on acute mortality as derived from acute oral exposure from laboratory tests. It does not address subacute behavioral or physiological effects that may occur prior to mortality and yet can still have a profound sub lethal effects on an organisms ability to survive and reproduce. As such, this index may underestimate ecological hazard from sub lethal exposures. For instance, it is common in clinical observations, conducted during acute tests, to observe such symptoms as wing droop, goose stepping ataxia, dyspnea ( labored breathing), diarrhea, apnea, weight loss, salivation, convulsions and hyperactivity prior to mortality occurring. Even if an organism survives this exposure to the toxicant, these symptoms indicate the organism is under extreme stress that could greatly affect both its survival ( susceptibility to disease and parasites, ability to avoid predation, nest desertion and abandonment) and ability to reproduce under actual field conditions. Necropsy data also indicate that many organisms are experiencing extreme physiological changes even though they may not die from exposure to the toxicant. Liver damage, renal failure, lesions, hemorrhage and other tissue damage are indications of severe physiological impairment that could adversely affect both the survival and reproductive capability of the organisms. These sub lethal effects are not really addressed by the LD50/ sq. ft. index. In fact, although the SAP ( 1996) approved the LD50/ sq. ft. index as a method for determining and classifying ecological risk to terrestrial wildlife from the use of granular formulations, it questioned the use of mortality as the primary end point for addressing ecological risk. The SAP stated that, " Many chemicals evoke toxicity through the interference with the physiological state of the animal including behaviors important to continued reproduction and survival. Each chemical may have certain unique qualities that may influence their potential hazard to wildlife." These comments suggest that basing ecological hazard assessments solely on direct effects, as determined by acute indices, may be under protective for predicting indirect effects from sub lethal exposures.

Although it is presumed that the LD50/ sq. ft. index accounts for acute exposure from oral, dermal and inhalation exposure, it was not intended to address exposure from drinking water where runoff, from either rain events or irrigation, to low areas may create puddles that contain very high concentrations of the pesticide. The contribution of this route of exposure to overall body burden residues is unknown but it will clearly be additive to exposure from direct consumption of the bait formualtion and/ or exposure from eating contaminated vegetation.

c. The Likelihood of Wildlife Presence at Time of Application Birds and mammals may utilize outdoor areas and animal premise areas that have been treated with dichlorvos and therefore may be exposed. Also, birds and mammals foraging for seeds, insects, and annelids ( e. g., earthworms) may be unable to avoid ingesting granular bait dichlorvos. Birds may also ingest granules in treated areas when foraging for grit.

d. Significance of Wildlife Utilization of Treatment Areas 55 Characterizing risk to non target wildlife from the use of dichlorvos on the areas for which it is registered, requires a clear understanding of the many limitations of identifying exactly what species are most likely to use treated areas and for what purpose. The simple fact is, wildlife utilization of animal premise areas and general outdoor areas is highly variable and difficult to predict and, as such, there is a great deal of uncertainty surrounding this issue when conducting an ecological hazard evaluation.

e. Routes of Exposure The risk assessment findings of acute risk to terrestrial animals is based on risk assessments where ingestion of contaminated food is considered as the primary route of exposure. The risk assessment did not consider the other possible routes of exposure, e. g., dermal, preening, and respiratory pathways. These other paths of exposure have been shown to contribute to acute toxicity of other organophosphate compounds ( Driver et al. 1991). Other routes of exposure, not considered in this assessment, are discussed below:

· Incidental soil ingestion exposure This risk assessment does not consider incidental soil ingestion. Available data suggests that up to 15% of the diet can consist of incidentally ingested soil depending on the species and feeding strategy ( Beyer et al., 1994).

· Inhalation exposure This risk assessment does not consider respiratory pathways. Since dichlorvos volatilizes rapidly, the inhalation route of exposure may contribute to acute toxicity. Incidence data reports avian toxicity due to inhalation exposure.

· Dermal Exposure The screening assessment does not consider dermal exposure, except as it is indirectly included in calculations of RQs based on lethal doses per unit of pesticide treated area. Dermal exposure may occur through two potential sources: ( 1) incidental contact with contaminated vegetation, or ( 2) contact with contaminated water or soil.

The available measured data related to wildlife dermal contact with pesticides are extremely limited. The Agency is actively pursuing modeling techniques to account for dermal exposure via incidental contact with vegetation.

· Drinking Water Exposure Drinking water exposure to a pesticide active ingredient may be the result of consumption of surface water or consumption of the pesticide in dew or other water on the surface of the treated area. For pesticide active ingredients with a potential to dissolve in runoff, puddles on the treated area may contain the chemical. Given its high water solubility, dichlorvos is expected to dissolve in dew and other water associated with plant surfaces. However, the likelihood of exposure to dichlorvos via drinking water is not quantified in the exposure modeling.

f. Incidental Pesticide Releases Associated with Use This risk assessment is based on the assumption that the entire treatment area is subject to dichlorvos application at the rates specified on the label. In reality, there is the potential for uneven application of the pesticide through such plausible incidents as changes in calibration of application equipment, spillage, and localized releases. 56 4. Assumptions and Limitations Related to Effects Assessment a. Age class and sensitivity of effects thresholds It is generally recognized that test organism age may have a significant impact on the observed sensitivity to a toxicant. The screening risk assessment acute toxicity data for fish are collected on juvenile fish between 0.1 and 5 grams. Aquatic invertebrate acute testing is performed on recommended immature age classes ( e. g., first instar for daphnids, second instar for amphipods, stoneflies and mayflies, and third instar for midges). Similarly, acute dietary testing with birds is also performed on juveniles, with mallard being 5 10 days old and quail 10 14 days old.

Testing of juveniles may overestimate toxicity at older age classes for pesticidal active ingredients, such as dichlorvos, that act directly because younger age classes may not have the enzymatic systems associated with detoxifying xenobiotics. The screening risk assessment has no current provisions for a generally applied method that accounts for this uncertainty. In so far as the available toxicity data may provide ranges of sensitivity information with respect to age class, the risk assessment uses the most sensitive life stage information as the conservative screening endpoint.

b.. Use of the Most Sensitive Species Tested Although the screening level risk assessment relies on a selected toxicity endpoint from the most sensitive species tested, it does not necessarily mean that the selected toxicity endpoints reflect sensitivity of the most sensitive species existing in a given environment. The relative position of the most sensitive species tested in the distribution of all possible species is a function of the overall variability among species to a particular chemical. In the case of listed species, there is uncertainty regarding the relationship of the listed species' sensitivity and the most sensitive species tested.

The Agency is not limited to a base set of surrogate toxicity information in establishing risk assessment conclusions. The Agency also considers toxicity data on non standard test species when available.

5. Assumptions Associated with the Acute LOCs The risk characterization section of the assessment document includes an evaluation of the potential for individual effects at an exposure level equivalent to the LOC. This evaluation is based on the median lethal dose estimate and dose/ response relationship established for the effects study corresponding to each taxonomic group for which the LOCs are exceeded.

6. Data Gaps and Limitations of the Risk Assessment The following data gaps were identified:

g. Ecotoxicity Data Gaps There is limited terrestrial and aquatic plant data for dichlorvos, which leads to uncertainty in the evaluation of plant risk.

c. Environmental Fate Information Gaps ere are no environmental fate data gaps.

Appendices A and B at the end of this document provides the summary status of all the environmental fate and ecotoxicological data requirement 57 58 REFERENCES Bennett, R. S. and L. M. Ganio. 1991. Overview of methods for evaluating effects of pesticides on reproduction in birds. U. S. EPA, Off. Research and Development, Environ. Res. Lab., Corvallis, Oregon. 106 p.

Best, L. B., R. C. Whitmore and G. M. Booth. 1990. Use of cornfields by birds during the breeding season: the importance of edge habitat. American Midland Naturalist 123: 84 99.

Driver et al. 1991. Routes of Uptake and their relative contribution to the toxicological response of northern bobwhite ( Colinus virginianus) to an organophoshate pesticide. Environmental Toxicology and Chemistry Vol. 10, pp. 21 33.

Felthousen, R. 1977. Classification of Granulated Formulations. USEPA, September 9, 1977 Goh, K. S. et al. 1986. Dissipation of Dislodgeable Foliar Residues of Chlorpyrifos and Dichlorvos on Turf. Bull. Environ. Contam. Toxicol., 37: 27 32.

Madrigal et al. 1996. Have to find the citation Mayer, F. L. J. and Ellersieck, M. R. 1986. Manual of Acute Toxicity: Interpretation and Data Base for 410 Chemicals and 66 Species of Freshwater Animals. Resour. Publ. No. 160, U. S. Dep. Interior, Fish Wildl. Serv., Washington, DC 505 p. ( USGS Data File) ( EPA MRID # 40098001).

Urban D. J. and N. J. Cook. 1986. Hazard Evaluation Division Standard Evaluation Procedure Ecological Risk Assessment. EPA 540/ 9 85 001. U. S. Environmental Protection Agency, Office of Pesticide Programs, Washington, DC.

U. S. EPA. 1986. Acute Toxicity Handbook of Chemicals to Estuarine Organisms., U. S. EPA, Gulf Breeze, FL ( US EPA MRID 40228401).

U. S. EPA. 1992. Comparative Analysis of Acute Avian Risk from Granular Pesticides. March, 1 9 9 2 .

U. S. EPA. 2004a. Interim Guidance of the Evaluation Criteria for Ecological Toxicity Data in the Open Literature, Phases I and II. July 16, 2004 U. S. EPA. 2004b. T REX Version 1.1. December 7, 2004 59 60 APPENDIX A. ECOLOGICAL DATA REQUIREMENTS FOR DICHLORVOS Data Requirements Use Pattern 1 Does EPA Have Data to Satisfy this Requirement? ( Yes, No, or Partially) Bibliographic Citation Must Additional Data be Submitted under FIFRA 3( c)( 2)( B)?

71 1( a) Acute Avian Oral, Quail/ Duck 3,8,9,11,15 Yes 40818301, 00160000 No 71 2( a) Acute Avian Diet, Quail 3,8,9,11,15 Yes 00022923 No 71 2( b) Acute Avian Diet, Duck 3,8,9,11,15 Yes 00022923 No 71 4( a) Avian Reproduction Quail 3 Yes 43981701 No 71 4( b) Avian Reproduction Duck 3 Yes 44233401 No 72 1( a) Acute Fish Toxicity Bluegill 3,8,9,11,15 Yes 40094602 No 72 1( b) Acute Fish Toxicity Bluegill ( TEP) 5 Yes 43284701 No2 72 1( c) Acute Fish Toxicity Rainbow Trout 3,8,9,11,15 Yes 40098001 No 72 1( d) Acute Fish Toxicity Rainbow Trout ( TEP) 5 Yes 43284702 No2 72 2( a) Acute Aquatic Invertebrate 3,8,9,11,15 Yes 40098001 No 72 3( a) Acute Est/ Mar Toxicity Fish 3 Yes 43571403 No 72 3( b) Acute Est/ Mar Toxicity Mollusk 3 Yes 43571404 No 72 3( c) Acute Est/ Mar Toxicity Shrimp 3 Yes 43571405 No 72 3( d) Acute 5 Yes 43571406 No2 61 Est/ Mar Toxicity Fish ( TEP)

72 3( e) Acute Est/ Mar Toxicity Mollusk ( TEP) 5 Yes 43571407 No2 72 3( f) Acute Est/ Mar Toxicity Shrimp ( TEP) 5 Yes 43571408 No2 72 4( a) Early Life Stage Fish 3 Yes 43788001, 43790401 No 72 4( b) Life Cycle Aquatic Invertebrate 3 Yes 43890301, 43854301 No 141 1 Honey Bee Acute Contact 3, 11 Yes 00036935 No 141 2 Honey bee Residue on Foliage 3, 11 Yes 43366701 No FOOTNOTES:

1. 1 = Terrestrial Food; 2 = Terrestrial Feed; 3 = Terrestrial Non Food; 4 = Aquatic Food; 5 = Aquatic Non Food ( Outdoor); 6 = Aquatic Non Food ( Industrial); 7 = Aquatic Non Food ( Residential); 8 = Greenhouse Food; 9 = Greenhouse Non Food; 10 = Forestry; 11 = Residential Outdoor; 12 = Indoor Food; 13 = Indoor Non Food; 14 = Indoor Medicinal; 15 = Indoor Residential 2. Although data are available, there is no longer an Aquatic Non Food ( Outdoor) or Terrestrial Food use for this chemical. 62 APPENDIX B. ENVIRONMENTAL FATE DATA REQUIREMENTS FOR DICHLORVOS Data Requirements Use Pattern 1 Does EPA Have Data to Satisfy this Requirement? ( Yes, No, or Partially) Bibliographic Citation Must Additional Data be Submitted under FIFRA 3( c)( 2)( B)?

161 1 Hydrolysis 3,8,9,11 Yes 41723101 No 161 2 Photodegradation in Water 3 Yes 43326601 No 161 3 Photodegradation On Soil 1 Yes 43642501 No2 162 1 Aerobic Soil 3,8,9,11 Yes 41723102 No 162 2 Anaerobic Soil 1 Yes 43835701 No2 163 1 Leaching  Adsorption/ Desorp. 3,8,9,11 Yes 41723103, 40034904 No 164 1 Soil Dissipation 3,11 Yes 44386701, 44297701 No 201 1 Droplet Size Spectrum 3 Yes No3 202 1 Drift Field Evaluation 3 Yes No3 FOOTNOTES:

1. 1 = Terrestrial Food; 2 = Terrestrial Feed; 3 = Terrestrial Non Food; 4 = Aquatic Food; 5 = Aquatic Non Food ( Outdoor); 6 = Aquatic Non Food ( Industrial); 7 = Aquatic Non Food ( Residential); 8 = Greenhouse Food; 9 = Greenhouse Non Food; 10 = Forestry; 11 = Residential Outdoor; 12 = Indoor Food; 13 = Indoor Non Food; 14 = Indoor Medicinal; 15 = Indoor Residential 2. Although data are available, there is no longer an Aquatic Non Food ( Outdoor) or Terrestrial Food use for this chemical.

3. Amvac is a member of the Spray Drift Task Force. 63 APPENDIX C. PRZM/ EXAMS MODELING FLORIDA TURF 1 APPLICATION at 0.2 lbs/ A stored as DVPtrf1. out Chemical: DDVP PRZM environment: FLturfC. txt modified Monday, 16 June EXAMS environment: pond298. exv modified Thuday, 29 August Metfile: w12834. dvf modified Wedday, 3 July 2002 Water segment concentrations ( ppb)

Year Peak 96 Hr 21 Day 60 Day 90 Day Yearly 1961 0.112 0.0867 0.03732 0.01389 0.009268 0.002285 1962 0.112 0.0867 0.03731 0.01389 0.009267 0.002285 1963 0.112 0.08675 0.03738 0.01392 0.009283 0.002289 1964 0.112 0.0867 0.03732 0.01389 0.009267 0.002279 1965 0.112 0.0867 0.03731 0.01389 0.009266 0.002285 1966 0.112 0.08672 0.03733 0.0139 0.009272 0.002286 1967 0.112 0.0867 0.03731 0.01389 0.009266 0.002285 1968 0.112 0.08671 0.03732 0.01389 0.009269 0.002279 1969 0.112 0.0867 0.03731 0.01389 0.009266 0.002285 1970 0.112 0.0867 0.03731 0.01389 0.009265 0.002285 1971 0.112 0.0867 0.03731 0.01389 0.009267 0.002285 1972 0.112 0.08671 0.03733 0.0139 0.00927 0.00228 1973 0.112 0.08671 0.03732 0.01389 0.009269 0.002286 1974 0.112 0.08671 0.03732 0.0139 0.009269 0.002286 1975 0.112 0.08671 0.03733 0.0139 0.00927 0.002286 1976 0.112 0.08717 0.0377 0.01404 0.009365 0.002303 1977 0.112 0.0867 0.03731 0.01389 0.009266 0.002285 1978 0.112 0.0867 0.03731 0.01389 0.009266 0.002285 1979 0.112 0.0867 0.03731 0.01389 0.009266 0.002285 64 1980 0.112 0.08677 0.03737 0.01391 0.00928 0.002282 1981 0.112 0.0867 0.03731 0.01389 0.009265 0.002285 1982 0.112 0.08671 0.03732 0.0139 0.009269 0.002286 1983 0.112 0.0867 0.03732 0.01389 0.009268 0.002286 1984 0.112 0.08691 0.0376 0.014 0.00934 0.002297 1985 0.1122 0.08721 0.03768 0.01403 0.009359 0.002308 1986 0.112 0.0867 0.03731 0.01389 0.009267 0.002285 1987 0.112 0.0867 0.03732 0.01389 0.009267 0.002285 1988 0.112 0.0867 0.03732 0.01389 0.009268 0.002279 1989 0.112 0.0867 0.03731 0.01389 0.009265 0.002285 1990 0.112 0.0867 0.03731 0.01389 0.009266 0.002285 Sorted results Prob. Peak 96 Hr 21 Day 60 Day 90 Day Yearly 0.03225806 0.1122 0.08721 0.0377 0.01404 0.009365 0.002308 0.06451613 0.112 0.08717 0.03768 0.01403 0.009359 0.002303 0.09677419 0.112 0.08691 0.0376 0.014 0.00934 0.002297 0.12903226 0.112 0.08677 0.03738 0.01392 0.009283 0.002289 0.16129032 0.112 0.08675 0.03737 0.01391 0.00928 0.002286 0.19354839 0.112 0.08672 0.03733 0.0139 0.009272 0.002286 0.22580645 0.112 0.08671 0.03733 0.0139 0.00927 0.002286 0.25806452 0.112 0.08671 0.03733 0.0139 0.00927 0.002286 0.29032258 0.112 0.08671 0.03732 0.0139 0.009269 0.002286 0.32258065 0.112 0.08671 0.03732 0.0139 0.009269 0.002286 0.35483871 0.112 0.08671 0.03732 0.01389 0.009269 0.002285 0.38709677 0.112 0.08671 0.03732 0.01389 0.009269 0.002285 0.41935484 0.112 0.0867 0.03732 0.01389 0.009268 0.002285 65 0.4516129 0.112 0.0867 0.03732 0.01389 0.009268 0.002285 0.48387097 0.112 0.0867 0.03732 0.01389 0.009268 0.002285 0.51612903 0.112 0.0867 0.03732 0.01389 0.009267 0.002285 0.5483871 0.112 0.0867 0.03732 0.01389 0.009267 0.002285 0.58064516 0.112 0.0867 0.03731 0.01389 0.009267 0.002285 0.61290323 0.112 0.0867 0.03731 0.01389 0.009267 0.002285 0.64516129 0.112 0.0867 0.03731 0.01389 0.009267 0.002285 0.67741935 0.112 0.0867 0.03731 0.01389 0.009266 0.002285 0.70967742 0.112 0.0867 0.03731 0.01389 0.009266 0.002285 0.74193548 0.112 0.0867 0.03731 0.01389 0.009266 0.002285 0.77419355 0.112 0.0867 0.03731 0.01389 0.009266 0.002285 0.80645161 0.112 0.0867 0.03731 0.01389 0.009266 0.002285 0.83870968 0.112 0.0867 0.03731 0.01389 0.009266 0.002282 0.87096774 0.112 0.0867 0.03731 0.01389 0.009266 0.00228 0.90322581 0.112 0.0867 0.03731 0.01389 0.009265 0.002279 0.93548387 0.112 0.0867 0.03731 0.01389 0.009265 0.002279 0.96774194 0.112 0.0867 0.03731 0.01389 0.009265 0.002279 0.1 0.112 0.086896 0.037578 0.013992 0.009334 0.002296 Average of yearly averages: 0.002286 Inputs generated by pe4. pl  8 Aug 03 Data used for this run: Output File: DVPtrf1 Metfile: w12834. dvf PRZM scenario: FLturfC. txt EXAMS environment file: pond298. exv Chemical Name: DDVP Description Variable Name Value Units Comment s Molecular weight mwt 220.9 g/ mol Henry's Law Const. henry 5.01E 08 atm m^ 3/ mol Vapor Pressure vapr 1.20E 02 torr 66 Solubility sol 10000 mg/ L Kd Kd mg/ L Koc Koc 37 mg/ L Photolysis half life kdp 10.2 days Half life Aerobic Aquatic Metabolism kbacw 0 days Halfife Anaerobic Aquatic Metabolism kbacs 0 days Halfife Aerobic Soil Metabolism asm 0.42 days Halfife Hydrolysis: pH 7 5.2 days Half life Method: CAM 2 integer See PRZM manual Incorporation Depth: DEPI 0 cm Application Rate: TAPP 0.224 kg/ ha Application Efficiency: APPEFF 0.99 fraction Spray Drift DRFT 0.01 fraction of applicatio Application Date Date 20 05 dd/ mm or dd/ mmm Record 17: 00 FILTRA IPSCND 1 UPTKF Record 18: 00 PLVKRT PLDKRT 2.64 FEXTRC 0.5 Flag for Index Res. Run IR Pond Flag for runoff calc. RUNOFF none none,

FLORIDA TURF 4 APPLICATIONS, 30 DAY INTERVAL, 0.2 lbs/ A stored as DVPFLtrf. out Chemical: DDVP PRZM environment : FLturfC. txt modified Monday, 16 June EXAMS environment : pond298. exv modified Thuday, 29 August Metfile: w12834. dvf modified Wedday, 3 July 2002 Water segment concentrations ( ppb)

Year Peak 96 Hr 21 Day 60 Day 90 Day Yearly 1961 0.114 0.09286 0.04047 0.02871 0.0284 0.009295 1962 0.1188 0.1001 0.04436 0.0302 0.0294 0.009537 1963 0.114 0.08831 0.03803 0.02781 0.02781 0.009148 1964 0.114 0.08833 0.03806 0.02782 0.02781 0.00912 1965 0.114 0.08831 0.03804 0.02781 0.02781 0.009143 1966 2.983 2.309 0.9941 0.3839 0.2653 0.06772 67 1967 0.114 0.08832 0.03804 0.02782 0.02781 0.009144 1968 0.1247 0.09659 0.0416 0.02954 0.02897 0.009406 1969 0.114 0.08832 0.03813 0.02785 0.02783 0.00915 1970 0.114 0.08833 0.03805 0.02782 0.02781 0.009144 1971 0.114 0.08831 0.03804 0.02782 0.02781 0.009144 1972 2.374 1.838 0.7913 0.3083 0.2149 0.05513 1973 0.114 0.08832 0.03804 0.02782 0.02781 0.009145 1974 0.114 0.08832 0.03804 0.02782 0.02781 0.009145 1975 0.114 0.08835 0.03806 0.02783 0.02782 0.009147 1976 0.114 0.08831 0.03803 0.02781 0.02781 0.009142 1977 0.114 0.08831 0.03811 0.02784 0.02782 0.009148 1978 0.114 0.08831 0.03803 0.02781 0.0278 0.009143 1979 0.114 0.08832 0.03804 0.02782 0.02781 0.009144 1980 0.114 0.08835 0.03812 0.02784 0.02784 0.009129 1981 0.114 0.08832 0.0381 0.02784 0.02782 0.009147 1982 0.1742 0.135 0.06278 0.03711 0.03401 0.01067 1983 0.114 0.08837 0.03809 0.02783 0.02782 0.009148 1984 0.1222 0.09999 0.04476 0.03035 0.0295 0.009552 1985 0.114 0.09034 0.0392 0.02825 0.0281 0.009239 1986 0.1143 0.09068 0.04065 0.02882 0.02848 0.009309 1987 0.114 0.08835 0.03806 0.02782 0.02781 0.009145 1988 0.114 0.08832 0.03804 0.02781 0.02781 0.009119 1989 0.114 0.08841 0.03808 0.02783 0.02781 0.009145 1990 0.114 0.08831 0.03803 0.02781 0.0278 0.009143 Sorted results Prob. Peak 96 Hr 21 Day 60 Day 90 Day Yearly 0.03225806 2.983 2.309 0.9941 0.3839 0.2653 0.06772 68 0.06451613 2.374 1.838 0.7913 0.3083 0.2149 0.05513 0.09677419 0.1742 0.135 0.06278 0.03711 0.03401 0.01067 0.12903226 0.1247 0.1001 0.04476 0.03035 0.0295 0.009552 0.16129032 0.1222 0.09999 0.04436 0.0302 0.0294 0.009537 0.19354839 0.1188 0.09659 0.0416 0.02954 0.02897 0.009406 0.22580645 0.1143 0.09286 0.04065 0.02882 0.02848 0.009309 0.25806452 0.114 0.09068 0.04047 0.02871 0.0284 0.009295 0.29032258 0.114 0.09034 0.0392 0.02825 0.0281 0.009239 0.32258065 0.114 0.08841 0.03813 0.02785 0.02784 0.00915 0.35483871 0.114 0.08837 0.03812 0.02784 0.02783 0.009148 0.38709677 0.114 0.08835 0.03811 0.02784 0.02782 0.009148 0.41935484 0.114 0.08835 0.0381 0.02784 0.02782 0.009148 0.4516129 0.114 0.08835 0.03809 0.02783 0.02782 0.009147 0.48387097 0.114 0.08833 0.03808 0.02783 0.02782 0.009147 0.51612903 0.114 0.08833 0.03806 0.02783 0.02781 0.009145 0.5483871 0.114 0.08832 0.03806 0.02782 0.02781 0.009145 0.58064516 0.114 0.08832 0.03806 0.02782 0.02781 0.009145 0.61290323 0.114 0.08832 0.03805 0.02782 0.02781 0.009145 0.64516129 0.114 0.08832 0.03804 0.02782 0.02781 0.009144 0.67741935 0.114 0.08832 0.03804 0.02782 0.02781 0.009144 0.70967742 0.114 0.08832 0.03804 0.02782 0.02781 0.009144 0.74193548 0.114 0.08832 0.03804 0.02782 0.02781 0.009144 0.77419355 0.114 0.08831 0.03804 0.02782 0.02781 0.009143 0.80645161 0.114 0.08831 0.03804 0.02781 0.02781 0.009143 0.83870968 0.114 0.08831 0.03804 0.02781 0.02781 0.009143 0.87096774 0.114 0.08831 0.03803 0.02781 0.02781 0.009142 69 0.90322581 0.114 0.08831 0.03803 0.02781 0.02781 0.009129 0.93548387 0.114 0.08831 0.03803 0.02781 0.0278 0.00912 0.96774194 0.114 0.08831 0.03803 0.02781 0.0278 0.009119 0.1 0.16925 0.13151 0.060978 0.036434 0.033559 0.010558 Average of yearly averages: 0.012728 Inputs generated by pe4. pl  8 Aug 03 Data used for this run: Output File: DVPFLtrf Metfile: w12834. dvf PRZM scenario: FLturfC. txt EXAMS environment file: pond298. exv Chemical Name: DDVP Description Variable Name Value Units Comment s Molecular weight mwt 220.9 g/ mol Henry's Law Const. henry 5.01E 08 atm m^ 3/ mol Vapor Pressure vapr 1.20E 02 torr Solubility sol 10000 mg/ L Kd Kd mg/ L Koc Koc 37 mg/ L Photolysis half life kdp 10.2 days Half life Aerobic Aquatic Metabolism kbacw 0 days Halfife Anaerobic Aquatic Metabolism kbacs 0 days Halfife Aerobic Soil Metabolism asm 0.42 days Halfife Hydrolysis: pH 7 5.2 days Half life Method: CAM 2 integer See PRZM manual Incorporation Depth: DEPI 0 cm Application Rate: TAPP 0.224 kg/ ha Application Efficiency: APPEFF 0.99 fraction Spray Drift DRFT 0.01 fraction of applicatio Application Date Date 20 05 dd/ mm or dd/ mmm Interval 1 interval 30 days Set to Interval 2 interval 30 days Set to Interval 3 interval 30 days Set to Record 17: 00 FILTRA IPSCND 1 UPTKF Record 18: 00 PLVKRT PLDKRT 2.64 FEXTRC 0.5 Flag for Index Res. Run IR Pond Flag for runoff calc. RUNOFF none none, 70 PENNSYLVANIA TURF 1 APPLICATION at 0.2 lbs/ A stored as DVPtrfPA. out Chemical: DDVP PRZM environment : PAturfC. txt modified Satday, 12 October EXAMS environment : pond298. exv modified Thuday, 29 August Metfile: w14737. dvf modified Wedday, 3 July 2002 Water segment concentration s ( ppb)

Year Peak 96 Hr 21 Day 60 Day 90 Day Yearly 1961 0.112 0.08672 0.03734 0.0139 0.009274 0.002287 1962 0.112 0.08672 0.03734 0.0139 0.009274 0.002287 1963 0.112 0.08672 0.03733 0.0139 0.009273 0.002287 1964 0.112 0.08671 0.03733 0.0139 0.009271 0.00228 1965 0.112 0.08671 0.03733 0.0139 0.009272 0.002287 1966 0.112 0.08672 0.03734 0.0139 0.009273 0.002287 1967 0.112 0.08672 0.03733 0.0139 0.009272 0.002287 1968 0.112 0.08672 0.03734 0.01391 0.009275 0.002281 1969 0.112 0.08671 0.03733 0.0139 0.009271 0.002286 1970 0.112 0.08672 0.03734 0.0139 0.009273 0.002287 1971 0.112 0.08672 0.03734 0.0139 0.009274 0.002287 1972 0.112 0.08672 0.03734 0.0139 0.009274 0.002281 1973 0.112 0.08672 0.03734 0.0139 0.009275 0.002287 71 1974 0.112 0.08672 0.03734 0.0139 0.009274 0.002287 1975 0.112 0.08673 0.03735 0.01391 0.009276 0.002288 1976 0.112 0.08672 0.03733 0.0139 0.009273 0.00228 1977 0.112 0.08671 0.03733 0.0139 0.009271 0.002286 1978 0.112 0.08672 0.03734 0.0139 0.009275 0.002287 1979 0.112 0.08678 0.03742 0.01393 0.009295 0.002292 1980 0.112 0.08672 0.03734 0.0139 0.009273 0.002281 1981 0.112 0.08671 0.03733 0.0139 0.009272 0.002287 1982 0.112 0.08672 0.03734 0.0139 0.009274 0.002287 1983 0.112 0.08686 0.03745 0.01394 0.009301 0.002294 1984 0.4776 0.3698 0.1592 0.05929 0.03955 0.009726 1985 0.112 0.08671 0.03733 0.0139 0.009272 0.002287 1986 0.112 0.08758 0.03798 0.01414 0.009435 0.002327 1987 0.112 0.08672 0.03733 0.0139 0.009272 0.002287 1988 0.112 0.08672 0.03734 0.0139 0.009274 0.002281 1989 0.112 0.08672 0.03734 0.0139 0.009275 0.002287 1990 0.112 0.08672 0.03734 0.0139 0.009273 0.002287 Sorted results Prob. Peak 96 Hr 21 Day 60 Day 90 Day Yearly 0.03225806 0.4776 0.3698 0.1592 0.05929 0.03955 0.009726 0.06451613 0.112 0.08758 0.03798 0.01414 0.009435 0.002327 0.09677419 0.112 0.08686 0.03745 0.01394 0.009301 0.002294 0.12903226 0.112 0.08678 0.03742 0.01393 0.009295 0.002292 0.16129032 0.112 0.08673 0.03735 0.01391 0.009276 0.002288 0.19354839 0.112 0.08672 0.03734 0.01391 0.009275 0.002287 0.22580645 0.112 0.08672 0.03734 0.0139 0.009275 0.002287 72 0.25806452 0.112 0.08672 0.03734 0.0139 0.009275 0.002287 0.29032258 0.112 0.08672 0.03734 0.0139 0.009275 0.002287 0.32258065 0.112 0.08672 0.03734 0.0139 0.009274 0.002287 0.35483871 0.112 0.08672 0.03734 0.0139 0.009274 0.002287 0.38709677 0.112 0.08672 0.03734 0.0139 0.009274 0.002287 0.41935484 0.112 0.08672 0.03734 0.0139 0.009274 0.002287 0.4516129 0.112 0.08672 0.03734 0.0139 0.009274 0.002287 0.48387097 0.112 0.08672 0.03734 0.0139 0.009274 0.002287 0.51612903 0.112 0.08672 0.03734 0.0139 0.009274 0.002287 0.5483871 0.112 0.08672 0.03734 0.0139 0.009273 0.002287 0.58064516 0.112 0.08672 0.03734 0.0139 0.009273 0.002287 0.61290323 0.112 0.08672 0.03734 0.0139 0.009273 0.002287 0.64516129 0.112 0.08672 0.03734 0.0139 0.009273 0.002287 0.67741935 0.112 0.08672 0.03733 0.0139 0.009273 0.002287 0.70967742 0.112 0.08672 0.03733 0.0139 0.009273 0.002287 0.74193548 0.112 0.08672 0.03733 0.0139 0.009272 0.002286 0.77419355 0.112 0.08672 0.03733 0.0139 0.009272 0.002286 0.80645161 0.112 0.08671 0.03733 0.0139 0.009272 0.002281 0.83870968 0.112 0.08671 0.03733 0.0139 0.009272 0.002281 0.87096774 0.112 0.08671 0.03733 0.0139 0.009272 0.002281 0.90322581 0.112 0.08671 0.03733 0.0139 0.009271 0.002281 0.93548387 0.112 0.08671 0.03733 0.0139 0.009271 0.00228 0.96774194 0.112 0.08671 0.03733 0.0139 0.009271 0.00228 0.1 0.112 0.086852 0.037447 0.013939 0.0093 0.002294 Average of yearly averages: 0.002535 Inputs generated by pe4. pl  8 Aug 03 73 Data used for this run: Output File: DVPtrfPA Metfile: w14737. dvf PRZM scenario: PAturfC. txt EXAMS environment file: pond298. exv Chemical Name: DDVP Description Variable Name Value Units Comment s Molecular weight mwt 220.9 g/ mol Henry's Law Const. henry 5.01E 08 atm m^ 3/ mol Vapor Pressure vapr 1.20E 02 torr Solubility sol 10000 mg/ L Kd Kd mg/ L Koc Koc 37 mg/ L Photolysis half life kdp 10.2 days Half life Aerobic Aquatic Metabolism kbacw 0 days Halfife Anaerobic Aquatic Metabolism kbacs 0 days Halfife Aerobic Soil Metabolism asm 0.42 days Halfife Hydrolysis: pH 7 5.2 days Half life Method: CAM 2 integer See PRZM manual Incorporatio n Depth: DEPI 0 cm Application Rate: TAPP 0.224 kg/ ha Application Efficiency: APPEFF 0.99 fraction Spray Drift DRFT 0.01 fraction of applicatio Application Date Date 20 05 dd/ mm or dd/ mmm Record 17: 00 FILTRA IPSCND 1 UPTKF Record 18: 00 PLVKRT PLDKRT 2.64 FEXTRC 0.5 Flag for Index Res. Run IR Pond Flag for runoff calc. RUNOFF none none,

PENNSYLVANIA TURF 4 APPLICATIONS, 30 DAY INTERVAL, 0.2 lbs/ A stored as DVPPAtrf. out Chemical: DDVP PRZM environment : PAturfC. txt modified Satday, 12 October EXAMS environment : pond298. exv modified Thuday, 29 August Metfile: w14737. dvf modified Wedday, 3 July 2002 Water segment concentrations ( ppb) 74 Year Peak 96 Hr 21 Day 60 Day 90 Day Yearly 1961 0.1141 0.08833 0.03807 0.02784 0.02783 0.00915 1962 0.114 0.08832 0.03805 0.02783 0.02782 0.009149 1963 0.1141 0.08865 0.03822 0.02789 0.02786 0.009159 1964 0.1141 0.08833 0.03805 0.02783 0.02782 0.009123 1965 0.114 0.08833 0.03806 0.02783 0.02782 0.009148 1966 0.114 0.08832 0.03804 0.02782 0.02781 0.009147 1967 0.1141 0.08833 0.03806 0.02783 0.02782 0.009149 1968 0.114 0.08833 0.03805 0.02783 0.02782 0.009124 1969 0.1141 0.08833 0.03807 0.02783 0.02783 0.009149 1970 0.1262 0.1047 0.04681 0.03112 0.03001 0.00969 1971 0.114 0.08832 0.03804 0.02782 0.02782 0.009148 1972 0.1142 0.09017 0.04004 0.02893 0.02856 0.009307 1973 0.114 0.08833 0.03805 0.02782 0.02782 0.009149 1974 0.1141 0.08834 0.03806 0.02783 0.02782 0.00915 1975 0.1142 0.09152 0.03976 0.02847 0.02825 0.009256 1976 0.114 0.08832 0.03805 0.02782 0.02782 0.009123 1977 0.26 0.2014 0.08673 0.04596 0.03991 0.01213 1978 0.1141 0.08834 0.03806 0.02783 0.02782 0.00915 1979 0.1141 0.08833 0.03806 0.02783 0.02782 0.009155 1980 0.114 0.08833 0.03805 0.02782 0.02782 0.009123 1981 0.1141 0.08862 0.03827 0.02792 0.02789 0.009164 1982 0.114 0.08833 0.03805 0.02782 0.02782 0.009149 1983 0.1496 0.1192 0.05453 0.03402 0.03195 0.01017 1984 0.4776 0.3698 0.1592 0.07293 0.05792 0.01657 1985 0.114 0.08833 0.03805 0.02783 0.02782 0.009148 1986 0.1141 0.08833 0.03805 0.02785 0.02784 0.009188 75 1987 0.114 0.08833 0.03809 0.02784 0.02784 0.009152 1988 0.1141 0.09001 0.03895 0.02816 0.02804 0.009178 1989 0.1142 0.09185 0.03993 0.02864 0.02837 0.009285 1990 0.114 0.08832 0.03805 0.02782 0.02782 0.009148 Sorted results Prob. Peak 96 Hr 21 Day 60 Day 90 Day Yearly 0.03225806 0.4776 0.3698 0.1592 0.07293 0.05792 0.01657 0.06451613 0.26 0.2014 0.08673 0.04596 0.03991 0.01213 0.09677419 0.1496 0.1192 0.05453 0.03402 0.03195 0.01017 0.12903226 0.1262 0.1047 0.04681 0.03112 0.03001 0.00969 0.16129032 0.1142 0.09185 0.04004 0.02893 0.02856 0.009307 0.19354839 0.1142 0.09152 0.03993 0.02864 0.02837 0.009285 0.22580645 0.1142 0.09017 0.03976 0.02847 0.02825 0.009256 0.25806452 0.1141 0.09001 0.03895 0.02816 0.02804 0.009188 0.29032258 0.1141 0.08865 0.03827 0.02792 0.02789 0.009178 0.32258065 0.1141 0.08862 0.03822 0.02789 0.02786 0.009164 0.35483871 0.1141 0.08834 0.03809 0.02785 0.02784 0.009159 0.38709677 0.1141 0.08834 0.03807 0.02784 0.02784 0.009155 0.41935484 0.1141 0.08833 0.03807 0.02784 0.02783 0.009152 0.4516129 0.1141 0.08833 0.03806 0.02783 0.02783 0.00915 0.48387097 0.1141 0.08833 0.03806 0.02783 0.02782 0.00915 0.51612903 0.1141 0.08833 0.03806 0.02783 0.02782 0.00915 0.5483871 0.1141 0.08833 0.03806 0.02783 0.02782 0.009149 0.58064516 0.1141 0.08833 0.03806 0.02783 0.02782 0.009149 0.61290323 0.114 0.08833 0.03805 0.02783 0.02782 0.009149 0.64516129 0.114 0.08833 0.03805 0.02783 0.02782 0.009149 76 0.67741935 0.114 0.08833 0.03805 0.02783 0.02782 0.009149 0.70967742 0.114 0.08833 0.03805 0.02783 0.02782 0.009148 0.74193548 0.114 0.08833 0.03805 0.02783 0.02782 0.009148 0.77419355 0.114 0.08833 0.03805 0.02782 0.02782 0.009148 0.80645161 0.114 0.08833 0.03805 0.02782 0.02782 0.009148 0.83870968 0.114 0.08832 0.03805 0.02782 0.02782 0.009147 0.87096774 0.114 0.08832 0.03805 0.02782 0.02782 0.009124 0.90322581 0.114 0.08832 0.03805 0.02782 0.02782 0.009123 0.93548387 0.114 0.08832 0.03804 0.02782 0.02782 0.009123 0.96774194 0.114 0.08832 0.03804 0.02782 0.02781 0.009123 0.1 0.14726 0.11775 0.053758 0.03373 0.031756 0.010122 Average of yearly averages: 0.009561 Inputs generated by pe4. pl  8 Aug 03 Data used for this run: Output File: DVPPAtrf Metfile: w14737. dvf PRZM scenario: PAturfC. txt EXAMS environment file: pond298. exv Chemical Name: DDVP Description Variable Name Value Units Comment s Molecular weight mwt 220.9 g/ mol Henry's Law Const. henry 5.01E 08 atm m^ 3/ mol Vapor Pressure vapr 1.20E 02 torr Solubility sol 10000 mg/ L Kd Kd mg/ L Koc Koc 37 mg/ L Photolysis half life kdp 10.2 days Half life Aerobic Aquatic Metabolism kbacw 0 days Halfife Anaerobic Aquatic Metabolism kbacs 0 days Halfife Aerobic Soil Metabolism asm 0.42 days Halfife Hydrolysis: pH 7 5.2 days Half life Method: CAM 2 integer See PRZM manual Incorporation Depth: DEPI 0 cm Application Rate: TAPP 0.224 kg/ ha Application Efficiency: APPEFF 0.99 fraction Spray Drift DRFT 0.01 fraction of applicatio Application Date Date 20 05 dd/ mm or dd/ mmm 77 Interval 1 interval 30 days Set to Interval 2 interval 30 days Set to Interval 3 interval 30 days Set to Record 17: 00 FILTRA IPSCND 1 UPTKF Record 18: 00 PLVKRT PLDKRT 2.64 FEXTRC 0.5 Flag for Index Res. Run IR Pond Flag for runoff calc. RUNOFF none none, 78 APPENDIX D. TERRESTRIAL EXPOSURE AND RQ CALCULATION  T REX MODEL T REX Version 1.1 December 7, 2004 The T REX spreadsheet has been developed by the Plant, Terrestrial Biology and Exposure Technical Teams. For information or questions concerning this spreadsheet, please contact John Ravenscroft or Edward Odenkirchen.

** NOTE**: Please save the spreadsheet file to you own computer first. Select ` File', then ` Save As' on the menu bar. Select the destination on your own hard drive ( usually set to C:). Do not modify the spreadsheet on the F: drive.

Scroll down to next section for instructions.

Introduction and Background This spreadsheet based model calculates the decay of a chemical applied to foliar surfaces for single or multiple applications. It uses the same principle as the batch code models FATE and TERREEC that calculate terrestrial exposure concentration estimates on plant surfaces following pesticide application. A first order decay assumption is used to determine the concentration at each day after initial application based on the concentration resulting from the initial and additional applications. The decay is calculated from the first order rate equation:

CT = Cie  kT or in log form:

ln ( CT/ Ci) = kT Where CT = concentration at time T = day zero. Ci = concentration, in parts per million ( PPM), present initially ( on day zero) on the surfaces. Ci is calculated by multiplying the application rate, in pounds active ingredient per acre, by 240 for short grass, 110 for tall grass, and 135 for broad leafed plants/ small insects and 15 for fruits/ pods/ large insects based on the Kenaga nomogram ( Hoerger and Kenaga, 1972) as modified by Fletcher ( 1994). For maximum concentrations, additional applications are converted from pounds active ingredient per acre to PPM on the plant surface and the additional mass added to the mass of the chemical still present on the surfaces on the day of application. k = If the foliar dissipation data submitted to EFED are found scientifically valid and statistically robust for a specific pesticide, the 90% upper confidence limit of the mean halflives should be used. When scientifically valid, statistically robust data are not available, EFED recommends the using a default half life value of 35 days. The use of the 35 day halflife is based on the highest reported value ( 36.9 days), as reported by Willis and McDowell ( Pesticide persistence on foliage, Environ. Contam. Toxicol, 100: 23 73, 1987). 79 T = time, in days, since the start of the simulation. The initial application is on day 0. The simulation is designed to run for 365 days.

The spreadsheet calculates the pesticide residue concentrations on each type of surface on a daily interval for one year. The maximum concentration during the year is calculated for both maximum and mean residues.

The calculated residue concentrations are used to calculate Avian and Mammalian risk quotient ( RQ) values. The maximum calculated concentration is divided by user input values for acute and chronic endpoints to give RQs for each type of plant surface.

How to use TREX TREX has been designed to be easy to use, yet maintain a level of flexibility needed for the multitude of chemicals and use patterns encountered by risk assessors. Throughout the spreadsheet, look for small red cell tags that contain additional information; just move the cursor over them to display the comment box. With the exception of the seed treatment exposure worksheet, all necessary data can be entered into the ` Input' worksheet.

Inputs An ` Input' worksheet has been included to increase consistency and transparency in the terrestrial exposure estimation process. The inputs used to calculate the amount of chemical present and estimate exposure are highlighted in blue, as well as consist of various drop down menus. These inputs include the following:

Chemical name: Enter either the chemical or common name used in the assessment Use: Enter the crop name and type of use Formulation: Enter the state of the chemical to be used ( e. g., liquid, spray, WP, flowable, etc.) % A. I.: Enter the % A. I. for the formulation ( from the label) Application Rate: The maximum label application rate ( pounds ai/ acre) Half life: The degradation half life for the dominant process ( days) Application Interval: The interval between repeated applications, from the label ( days) Maximum # Application per year: From the label Concentration of Concern: For graphing purposes, choose an endpoint ( mg/ kg diet) that you wish to be overlaid onto the residue graph Choose label: From the drop down menu, choose the label that corresponds to the Concentration of Concern NOTE: Pushing the ` reset model' button to the right of the first set of inputs will clear ALL of the user supplied information. This button was included to allow the user to more quickly run multiple scenarios with TREX without having to manually clear each cell.

Endpoints TREX requires that both the chosen endpoint ( entered in the blue cell) and the test species to be included ( chosen from the drop down menu options). For example, one would enter an avian LD50 of 500 mg/ kg bw and that this endpoint was based on a Bobwhite quail study ( i. e., chosen from the drop down menu immediately to the right of the LD50 input cell). For now, this requirement is limited to the avian endpoints. 80 Avian endpoints Enter the endpoints in the blue cells and choose the corresponding test species from the drop down menus.

Mammalian endpoints For acute endpoints, enter the data in the blue cells. For chronic endpoints, enter the reported number and then choose whether this datapoint was a dose or diet based endpoint from the drop down menu. The other endpoint will then be calculated and displayed in the cell below.

LD50 ft 2 TREX includes the capability to also calculate an LD50 ft  2 with the above supplied information. Choose from the drop down menu provided whether or not you wish to do so. If ` yes' is chosen, the type of application method ( i. e., broadcast or rows) should be entered. If ` rows' is chosen, additional input parameters will be required ( i. e., row spacing, bandwidth, and % incorporation) and appear to the right. Next, input whether the application is a granular or liquid application. If ` liquid' is chosen, enter the oz. product per 1000 ft row.

To see the results, choose the LD50 ft  2 worksheet tab. The print area has been pre set, so choose the printer button in the toolbar to print.

Terrestrial Exposures All calculated Estimated Environmental Concentration ( EEC) and RQ values are presented in yellow. Intermediate calculations are displayed in red. Users may find these intermediate values useful in their assessment, so they are presented.

Upper Bound and Mean Kenaga Residue Worksheets Both the upper bound and mean Kenaga residues for the various food categories are provided. Each includes RQs for birds and mammals. The upper bound residue worksheet is to be used for reporting RQ values in the risk assessment, while the mean residue worksheet is solely for risk description purposes. Mean residues are calculated exactly as the maximum residues are, except the corresponding Kenaga values are 85 for Short Grass, 36 for Tall Grass, and 45 for Broad leafed plants/ small insects and 7 for fruits/ pods/ large insects.

In both worksheets, dose based RQs are calculated using a body weight adjusted LD50 and consumption weighted equivalent dose. The scaling factors ( USEPA, 1993) used in the consumption weighted ( EECs) are:

Avian consumption 81 Mammal consumption These consumption weighted EECs ( i. e., EEC equivalent dose) are sorted by food source and body size. There is a corresponding table for birds and mammals.

The LD50 values entered on the input form are adjusted for animal class ( 20, 100 and 1000 g birds and 15, 35, and 1000 g mammals) using the following equations:

Avian LD50 Mammal LD50 The dose based RQs are calculated by dividing the daily dose ( EEC equivalent dose) by the adjusted LD50 for each food category and animal class.

For dietary based RQs, the Kenaga EEC is divided by the LC50 ( acute RQ) or the NOAEC ( chronic RQ).

Graphs Each worksheet contains a graph of the calculated residues for the first 100 days and includes the ` Concentration of Concern' overlay from the input form. These can be copy/ pasted individually into a word processing program and used in the risk assessment, if desired. Additionally, graphs displaying acute and chronic LOCs for both birds and mammals are displayed in the ` Graph' worksheet.

LD50 ft 2 LD50 ft  2 values are calculated for both broadcast and banded ( granular and liquid) applications using the adjusted LD50 method described above. The results are presented by class for both birds and mammals for each type of application. 82 Seed Treatments Due to the difference in foliar application and seed treatment uses of pesticides, this worksheet can be used as a ` stand alone' tool for estimating avian and mammalian RQs for the various crops listed. Efforts were made to make this crop list as complete as possible; however, there may be additional crops added in the future as the need arises. Only those seed treatments needed for the assessment need to be entered. For example, if rye is not an intended use, then leave it set to zero, as this will have no impact on the RQ calculations for the other crops.

The seed treatment worksheet contains additional input cells in blue separate from those in the Input worksheet including:

Name of seed treatment formulation: Labels for seed treatment products differ from foliar applied formulations.

Percent A. I. in formulation: Enter % A. I. as a whole number ( e. g., 24% = 24)

Test body weights: Enter the test organism body weight from the avian and mammal studies Application rate ( fl oz./ cwt): Provided on the label NOTE: If a liquid rate is not available for a chemical, enter the dry weight application rate in the adjoining cell. Once this is done; however, the underlying equation in that cell has been replaced. It is preferable that users input the fl oz/ cwt value.

RQs are calculated using the adjusted LD50 for the smallest weight class of animal. Acute RQs are calculated using two methods:

Method # 1: Acute RQ = mg A. I. day  1 / adjusted LD50 Method # 2: Acute RQ = mg A. I. ft  2 /( adjusted LD50 * body weight)

Chronic RQs are calculated using the equation:

Chronic RQ = mg A. I. kg  1 seed/ NOAEL References Fletcher, J. S., J. E. Nellesson and T. G. Pfleeger. 1994. Literature review and evaluation of the EPA food chain ( Kenaga) nomogram, an instrument for estimating pesticide residues on plants. Environ. Tox. And Chem. 13( 9): 1383 1391 Hoerger, F. and E. E. Kenaga. 1972. Pesticide residues on plants: correlation of respresentative dada as a basis for estimation of their magnitude in the environment. IN: F. Coulston and F. Corte, eds., Environmental Quality and Safety: Chemistry, Toxicology and Technology. Vol 1. Georg Theime Publishers, Stuttgart, Germany. pp. 9 28 83 USEPA. 1993. Wildlife Exposure Factors Handbook. Volume I of II. EPA/ 600/ R 93/ 187a. Office of Research and Development, Washington, D. C. 20460.

Willis and McDowell. 1987. Pesticide persistence on foliage. Environ. Contam. Toxicol. 100: 23 73 84 TURF  1 APPLICATION AT 0.2 LBS/ A Chemical Name: Dichlorvos Use Turf Formulation Liquid spray Application Rate 0.0804 lbs a. i./ acre Half life 0.0875 days Application Interval 0 days Maximum # Apps./ Year 1 Length of Simulation 1 year Concentration of Concern 0.00 ( ppm)

Name of Concentration of Concern FALSE Endpoints Avian Mallard duck LD50 ( mg/ kgbw 7.78 Mallard duck LC50 ( mg/ kgdiet 568 Bobwhite quail NOAEL ( mg/ kg bw) 0 Mallard duck NOAEC ( mg/ kgdiet 5 Mammals LD50 ( mg/ kg bw) 56 LC50 ( mg/ kg diet) 0 NOAEL ( mg/ kg bw) 1 NOAEC ( mg/ kg diet) 20 EECs ( ppm) Kenaga Values Short Grass 19.30 Tall Grass 8.84 Broadleaf plants/ sm Insects 10.85 Fruits/ pods/ seeds/ lg insects 1.21 Avian Results 85 Avian Body % body wgt Adjusted Class Weight consumed LD50 Small 20 114 4.04 Mid 100 65 5.14 Large 1000 29 7.26 EEC equivalent dose ( mg/ kg bw) Avian Classes and Body Weights small mid large 20 g 100 g 1000 g Short Grass 22 13 6 Tall Grass 10 6 3 Broadleaf plants/ sm Insects 12 7 3 Fruits/ pods/ lg insects 1 1 0 Dose based RQs ( daily dose/ LD50) Avian Acute RQs 20 g 100 g 1000 g Short Grass 5.45 2.44 0.77 Tall Grass 2.50 1.12 0.35 Broadleaf plants/ sm insects 3.06 1.37 0.43 Fruits/ pods/ lg insects 0.34 0.15 0.05 Dietarybased RQs ( EEC/ LC50 or NOAEC) RQs Acute Chronic Short Grass 0.03 3.86 Tall Grass 0.02 1.77 Broadleaf plants/ sm Insects 0.02 2.17 Fruits/ pods/ lg insects 0.00 0.24 86 Mammalian Results Mammalian Body % body wgt Adjusted Adjusted Class Weight consume d LD50 NOAEL 15 95 123.08 2.20 Herbivores/ 35 66 99.58 1.78 insectivores 1000 15 43.07 0.77 15 21 123.08 2.20 Grainvores 35 15 99.58 1.78 1000 3 43.07 0.77 EEC equivalent dose ( mg/ kg bw) Mammalian Classes and Body weight Herbivores/ insectivores Granivore s 15 g 35 g 1000 g 15 g 35 g 1000 g Short Grass 18 13 3 Tall Grass 8 6 1 Broadleaf plants/ sm Insects 10 7 2 Fruits/ pods/ seeds/ lg insects 1 1 0 0 0 0 Dose based RQs ( daily dose/ LD50 or NOAEL) 15 g mammal 35 g mammal 1000 g mammal Acute Chronic Acute Chronic Acute Chronic Short Grass 0.15 8.34 0.13 7.16 0.07 3.76 87 Tall Grass 0.07 3.82 0.06 3.28 0.03 1.72 Broadleaf plants/ sm insects 0.08 4.69 0.07 4.03 0.04 2.12 Fruits/ pods/ lg insects 0.01 0.52 0.01 0.45 0.00 0.24 Seeds ( granivore) 0.00 0.12 0.00 0.10 0.00 0.05 Dietarybased RQs ( EEC/ LC50 or NOAEC) Mammal RQs Acute Chronic Short Grass 0.96 Tall Grass 0.44 Broadleaf plants/ sm insects 0.54 Fruits/ pods/ seeds/ lg insects 0.06 88 89 TURF  4 APPLICATION, 30 DAY APPLICATION INTERVALS, AT 0.2 LBS/ A Chemical Name: Dichlorvos Use Turf Formulation Liquid spray Application Rate 0.0804 lbs a. i./ acre Half life 0.0875 days Application Interval 30 days Maximum # Apps./ Year 4 Length of Simulation 1 year Concentration of Concern 0.00 ( ppm)

Name of Concentration of Concern FALSE Endpoints Avian Mallard duck LD50 ( mg/ kg bw) 7.78 Mallard duck LC50 ( mg/ kg diet) 568 Bobwhite quail NOAEL ( mg/ kg bw) 0 Mallard duck NOAEC ( mg/ kg diet) 5 Mammals LD50 ( mg/ kg bw) 56 LC50 ( mg/ kg diet) 0 NOAEL ( mg/ kg bw) 1 NOAEC ( mg/ kg diet) 20 EECs ( ppm) Kenaga Values Short Grass 19.30 Tall Grass 8.84 Broadleaf plants/ sm Insects 10.85 Fruits/ pods/ seeds/ lg insects 1.21 Avian Results Avian Body % body Adjusted 90 wgt Class Weight consume d LD50 Small 20 114 4.04 Mid 100 65 5.14 Large 1000 29 7.26 EEC equivalent dose ( mg/ kg bw) Avian Classes and Body Weights small mid large 20 g 100 g 1000 g Short Grass 22 13 6 Tall Grass 10 6 3 Broadleaf plants/ sm Insects 12 7 3 Fruits/ pods/ lg insects 1 1 0 Dose based RQs ( daily dose/ LD50) Avian Acute RQs 20 g 100 g 1000 g Short Grass 5.45 2.44 0.77 Tall Grass 2.50 1.12 0.35 Broadleaf plants/ sm insects 3.06 1.37 0.43 Fruits/ pods/ lg insects 0.34 0.15 0.05 Dietarybased RQs ( EEC/ LC50 or NOAEC) RQs Acute Chronic Short Grass 0.03 3.86 Tall Grass 0.02 1.77 Broadleaf plants/ sm Insects 0.02 2.17 91 Fruits/ pods/ lg insects 0.00 0.24 92 Mammalian Results Mammalian Body % body wgt Adjusted Adjusted Class Weight consume d LD50 NOAEL 15 95 123.08 2.20 Herbivores/ 35 66 99.58 1.78 insectivores 1000 15 43.07 0.77 15 21 123.08 2.20 Grainvores 35 15 99.58 1.78 1000 3 43.07 0.77 EEC equivalent dose ( mg/ kg bw) Mammalian Classes and Body weight Herbivores/ insectivores Granivore s 15 g 35 g 1000 g 15 g 35 g 1000 g Short Grass 18 13 3 Tall Grass 8 6 1 Broadleaf plants/ sm Insects 10 7 2 Fruits/ pods/ seeds/ lg insects 1 1 0 0 0 0 Dose based RQs ( daily dose/ LD50 or NOAEL) 15 g mammal 35 g mammal 1000 g mammal Acute Chronic Acute Chronic Acute Chronic Short Grass 0.15 8.34 0.13 7.16 0.07 3.76 Tall Grass 0.07 3.82 0.06 3.28 0.03 1.72 Broadleaf plants/ sm insects 0.08 4.69 0.07 4.03 0.04 2.12 Fruits/ pods/ lg insects 0.01 0.52 0.01 0.45 0.00 0.24 Seeds ( granivore) 0.00 0.12 0.00 0.10 0.00 0.05 93 Dietarybased RQs ( EEC/ LC50 or NOAEC) Mammal RQs Acute Chronic Short Grass 0.96 Tall Grass 0.44 Broadleaf plants/ sm insects 0.54 Fruits/ pods/ seeds/ lg insects 0.06 94 FLYING INSECT  0.2 LBS/ A Chemical Name: Dichlor vos Use Flying Insect Formulation Liquid spray Application Rate 0.0804 lbs a. i./ acre Half life 0.0875 days Application Interval 5 days Maximum # Apps./ Year 75 Length of Simulation 1 year Concentration of Concern 0.00 ( ppm)

Name of Concentration of Concern FALSE Endpoints Avian Mallard duck LD50 ( mg/ kg bw) 7.78 Mallard duck LC50 ( mg/ kg diet) 568 Bobwhite quail NOAEL ( mg/ kg bw) 0 Mallard duck NOAEC ( mg/ kg diet) 5 Mammals LD50 ( mg/ kg bw) 56 LC50 ( mg/ kg diet) 0 NOAEL ( mg/ kg bw) 1 NOAEC ( mg/ kg diet) 20 EECs ( ppm) Kenaga Values Short Grass 19.30 Tall Grass 8.84 Broadleaf plants/ sm Insects 10.85 Fruits/ pods/ seeds/ lg insects 1.21 Avian Results Avian Body % body Adjusted 95 wgt Class Weight consume d LD50 Small 20 114 4.04 Mid 100 65 5.14 Large 1000 29 7.26 EEC equivalent dose ( mg/ kg bw) Avian Classes and Body Weights small mid large 20 g 100 g 1000 g Short Grass 22 13 6 Tall Grass 10 6 3 Broadleaf plants/ sm Insects 12 7 3 Fruits/ pods/ lg insects 1 1 0 Dose based RQs ( daily dose/ LD50) Avian Acute RQs 20 g 100 g 1000 g Short Grass 5.45 2.44 0.77 Tall Grass 2.50 1.12 0.35 Broadleaf plants/ sm insects 3.06 1.37 0.43 Fruits/ pods/ lg insects 0.34 0.15 0.05 Dietarybased RQs ( EEC/ LC50 or NOAEC) RQs Acute Chronic Short Grass 0.03 3.86 Tall Grass 0.02 1.77 Broadleaf plants/ sm Insects 0.02 2.17 96 Fruits/ pods/ lg insects 0.00 0.24 97 Mammalian Results Mammalian Body % body wgt Adjusted Adjusted Class Weight consume d LD50 NOAEL 15 95 123.08 2.20 Herbivores/ 35 66 99.58 1.78 insectivores 1000 15 43.07 0.77 15 21 123.08 2.20 Grainvores 35 15 99.58 1.78 1000 3 43.07 0.77 EEC equivalent dose ( mg/ kg bw) Mammalian Classes and Body weight Herbivores/ insectivores Granivore s 15 g 35 g 1000 g 15 g 35 g 1000 g Short Grass 18 13 3 Tall Grass 8 6 1 Broadleaf plants/ sm Insects 10 7 2 Fruits/ pods/ seeds/ lg insects 1 1 0 0 0 0 Dose based RQs ( daily dose/ LD50 or NOAEL) 15 g mammal 35 g mammal 1000 g mammal Acute Chronic Acute Chronic Acute Chronic Short Grass 0.15 8.34 0.13 7.16 0.07 3.76 Tall Grass 0.07 3.82 0.06 3.28 0.03 1.72 Broadleaf plants/ sm insects 0.08 4.69 0.07 4.03 0.04 2.12 Fruits/ pods/ lg insects 0.01 0.52 0.01 0.45 0.00 0.24 Seeds ( granivore) 0.00 0.12 0.00 0.10 0.00 0.05 98 Dietarybased RQs ( EEC/ LC50 or NOAEC) Mammal RQs Acute Chronic Short Grass 0.96 Tall Grass 0.44 Broadleaf plants/ sm insects 0.54 Fruits/ pods/ seeds/ lg insects 0.06 99 BAIT 1 APPLICATION, 0.1 LBS/ A Chemical: Dichlorvos LD50 ft 2 INPUTS Do not overwrite these numbers.

Application Rate: 0.1 lbs ai/ acre % A. I.: 0.0744 Avian LD50 ( 20g): 4.04 mg/ kg bw ( 100g) 5.14 ( 1000g) 7.26 Mammalian LD50 ( 15g): 123.08 mg/ kg bw ( 35g) 99.58 ( 1000g) 43.07 Row Spacing: 0 inches Bandwidth: 0 inches Unincorporation: 100%

Broadcast applications Granular Intermediate Calculations mg ai/ ft2: 0.08 LD50 ft 2 wgt class Avian 20 g 0.959 100 g 0.151 1000 g 0.011 Mammal 15 g 0.042 35 g 0.022 1000 g 0.002 100