Emission scenario document for biocides used as rodenticides Jørgen Larsen

JOINTRESEARCHCENTRE

EUROPEAN COMMISSIONEuropean Chemicals Bureau

Emission scenario document for Emission scenario document for biocides used as rodenticidesbiocides used as rodenticides

Jørgen LarsenJørgen Larsen

PT 8 & PT 14 Exposure Scenario Course9-10 October 2003, Ispra

This presentationThis presentation

General issues and background Basic use and exposure scenarios of the

environment Exposure scenarios for primary poisoning Exposure scenarios for secondary poisoning Conclusions

Life-cycle of rodenticidesLife-cycle of rodenticidesProduction

Formulation

Private use

Processing In product

professional use

In product Processing

Service life

Waste treatment Primary and secondary poisoning

PT 14 RodenticidesPT 14 Rodenticides

Used for controlling rodents Rats Mice Voles

Basic use scenarios Sewer systems Buildings (inside and around) Open fields Waste dumps

Rodenticides: Application methodsRodenticides: Application methods

Scenario: Sewer Buildings Open fields

Waste dumps

Wax blocks ü ü ü ü

Grain / pellets ü ü ü ü

Bait box ü ü üContact powder ü ü

Liquid üFumigation ü

Rodenticides: Compartments of concernRodenticides: Compartments of concern

Scenario: Sewer Buildings Open fields

Waste dumps

STP ü üSurface water üSoil ü ü ü üAirPrimary poisoning

ü ü ü

Secondary poisoning

ü ü ü ü

Sewer systems: AssumptionsSewer systems: Assumptions

Realistic worst-case: 21 days campaign Day 0: 300 wax blocks Day 7: 100 wax blocks replenished Day 14: 50 wax blocks replenished

Maximum emission during 1st week: 100 blocks Weight of wax block: 0.3 kg Fraction of a.i. (substance) released: 0.9 Standard STP scenario (TGD)

200 L/day, 10,000 inhabitants

Sewer systems: STPSewer systems: STP

Variable/parameter (unit) Symbol Unit DefaultInput:Amount of product used in control operation

Qprod kg 30

Fraction of active substance in product Fcproduct DossierNumber of emission days (control operation)

Temission Days 7

Fraction of product released Freleased 0.3 + (0.6-*)Output:Local emission of active substance to waste water during episode

Elocalwater kg.d-1

releasedproductprod

water FTemission

FcQElocal

Sewer systems: ResultsSewer systems: Results

Substance A: Anti-coagulant (0.005% a.i.)

Elocalwater: 0.2 g a.i./day Cinfluent: 0.1 μg a.i./L

Substance B: Coagulant (4% a.i.)

Elocalwater: 150 g a.i./day Cinfluent: 77 μg a.i./L

Sewer systems: ResultsSewer systems: Results

Result depends on Used amount of product (Qprod) Fraction of a.i. in product (Fcproduct) Fraction of release (Freleased)

Estimation of PEClocal Fate (degradation, sorption, volatilisation) in STP

(presence of STP is default for local scenario) Dilution in aquatic environment PEClocalwater

Disposal of sludge on farmland PEClocalsoil

In and around buildingsIn and around buildings Assumptions on bait stations Assumptions on bait stations

Realistic worst-case: 21 days campaign Bait stations: 10 No. of replenishments: 5

Weight of wax block: 0.25 kg Fraction released due to spillage: 0.01 Spillage area: 0.09 m2 (0.1 m around station) Fraction ingested: 0.99 Fraction released of ingested: 0.9 Frequented area: 550 m2 (10 m around building)

Buildings: Direct emissionBuildings: Direct emission

Variable/parameter (unit) Symbol Unit Default

Input:Amount of product used in control operation for each bait box

Qprod g

Fraction of active substance in product Fcprod

Number of application sites Napp 10Number of refilling times Nrefil 5Fraction of product released directly to soil Frelease-D, soil 0.01

Output:Local direct emission rate of active substance to soil from a campain

Elocalsoil-campain g/campain

soilDreleaserefilappprodprodcampaignsoil FNNFcQElocal ,

Buildings: Direct soil exposureBuildings: Direct soil exposure

Variable/parameter (unit) Symbol Unit DefaultInput:Local emission to soil from a campaign Elocalsoil-campaign g

Area directly exposed to rodenticide AREAexposed-D m2 0.09Depth of exposed soil DEPTHsoil m 0.1Density of exposed soil RHOsoil kg/m3 1700Output:Local concentration in soil due to direct release after a campaign

Clocalsoil-D mg/kg

appsoilsoilDosed

campainsoilDsoil NRHODEPTHAREA

ElocalClocal

exp

310

Buildings: Indirect emissionBuildings: Indirect emission

Input:Amount of product used in control operation for each bait box

Qprod g


Number of application sites Napp 10Number of refilling times Nrefil 5Fraction of product ingested Fingested 0.99Fraction of ingested product released Frelease-ID, soil 0.9

Output:Local indirect emission rate of active substance to soil from a campain

Elocalsoil-campain g/campain

soilIDreleaseingestedrefilappprodprodcampaignsoil FFNNFcQElocal ,

Buildings: Indirect soil exposureBuildings: Indirect soil exposure

Variable/parameter (unit) Symbol Unit DefaultLocal emission rate to soil from a campaign Elocalsoil-campaign g/campaign

Area indirectly exposed to rodenticide AREAexposed-ID m2 550Depth of exposed soil DEPTHsoil m 0.1Density of wet soil RHOsoil kg/m3 1700Concentration in soil due to indirect (disperse) release after a campaign

Clocalsoil-ID mg/kg

soilsoilIDosed

campaignsoilIDsoil RHODEPTHAREA

ElocalClocal

exp

310

Buildings: Results re. bait stationsBuildings: Results re. bait stations


Elocal-D: 0.006 g a.i. Clocal-D: 0.04 mg a.i./kg Elocal-ID: 0.56 g a.i. Clocal-ID: 0.006 mg a.i./kg Clocal-D+ID: 0.047 mg/kg


Elocal-D: 5 g a.i. Clocal-D: 33 mg a.i./kg Elocal-ID: 446 g a.i. Clocal-ID: 4.8 mg a.i./kg Clocal-D+ID: 37 mg/kg

Open areas: AssumptionsOpen areas: Assumptionsre. pellets and impregnated grainre. pellets and impregnated grain

Pellets or impregnated grain used in rat burrow Entrance holes are sealed after application Product used: 0.1 kg Soil volume: 0.0085 m3 (lower half of 0.3 m

burrow, 0.1 m from the wall) Fraction released during application: 0.05 Fraction released during use: 0.2 Refills: 2

Open areas: Emission in rat burrowOpen areas: Emission in rat burrow

Variable/parameter (unit) Symbol Unit DefaultInput:Amount of product used in control operation Qprod gFraction of active substance in product Fcprod

Number of application sites Napp 1Number of refilling times Nrefil 2Fraction of product released to soil during application

Frelease, soil, appl 0.05

Fraction of product released to soil during use

Frelease, soil, use 0.2

Output:Local emission of active substance to soil during a campaign

Elocalsoil-campaign g

)( ,,,, usesoilreleaseapplsoilreleaserefilappprodprodcampaignsoil FFNNFcQElocal

Open areas: Concentration in rat burrowOpen areas: Concentration in rat burrow

soilosed

campaignsoilsoil RHOVsoil

ElocalClocal

exp

310

Variable/parameter (unit) Symbol Unit DefaultInput:Local emission to soil from the episode Elocalsoil-campaign gSoil volume exposed to rodenticide Vsoilexposed m3 0.0085

Density of wet exposed soil RHOsoil Kg/m3 1700Output:Local concentration in soil after a campaign Clocalsoil-campaign mg/kg

Open areas: Results, pellets in rat burrowOpen areas: Results, pellets in rat burrow


Elocal-D: 0.0025 g a.i. Clocal-D: 0.17 mg a.i./kg


Elocal-D: 2 g a.i. Clocal-D: 138 mg a.i./kg

Open areas: AssumptionsOpen areas: Assumptionsre. contact powderre. contact powder

Contact powder often used when plenty of food is available

Contact powder applied directly in burrow by spoon or dust-blower

Soil volume: 0.0085 m3 Fraction released to soil: 0.9 Product used: 0.1 kg (example)

Open areas: Release of contact powderOpen areas: Release of contact powder

Variable/parameter (unit) Symbol Unit DefaultInput:Amount of product used in control operation Qprod g


Number of application sites Napp 1Fraction of product released to soil Frelease, soil, 0.9Output:Local emission of active substance to soil after a campaign

Elocalsoil-campaign g

soilreleaseappprodprodcampainsoil FNFcQElocal ,

Open areas: Results, contact powderOpen areas: Results, contact powder


Elocal-D: 0.0045 g a.i. Clocal-D: 0.3 mg a.i./kg


Elocal-D: 3.6 g a.i. Clocal-D: 250 mg a.i./kg

Primary poisoning: Estimated Daily IntakePrimary poisoning: Estimated Daily Intake

FIR: Food intake rate of indicator species(gram fresh weight per day)

BW: Body weight (g) C: Concentration of compound in fresh diet (mg/kg) AV: Avoidance factor (0 to 1) PT: Fraction of diet obtained in treated area (0 to 1)PD: Fraction of food type in diet (0 to 1)

)//( dkgbwmgPDPTAVCBWFIREDI

Regression equations to predict dry Regression equations to predict dry weight intake for an animal (Nagy, 1987)weight intake for an animal (Nagy, 1987)

For all birds: log DFI = 0.651 x log BW - 0.188

For songbirds: log DFI = 0.85 x log BW - 0.4

For other birds: log DFI = 0.751 x log BW - 0.521

For mammals: log DFI = 0.822 x log BW - 0.629

Daily food intake of the indicator speciesDaily food intake of the indicator species

)100/())100/(1(( AEMCFEDEEFIR

FIR: Food intake rate of indicator species(gram fresh weight per day)

DEE: Daily Energy Expenditure of the indicator species (kJ per day) FE: Food Energy (kJ per dry gram)MC: Moisture Content (%) AE: Assimilation Efficiency (%)

From Crocker et al. 2002

Comparison of daily food intake based on Comparison of daily food intake based on different calculation methods different calculation methods

Bird Method Body Wt Mean food intake*

Song birds:Tree sparrow; Passer montanus Nagy 1987 22.0 g 6.3 gTree sparrow; Passer montanus Croker et al. 02 22.0 g 7.6 gRook; Corvus frugeligus Nagy 1987 488.0 g 87.0 gRook; Corvus frugeligus Croker et al. 02 488.0 g 67.5 g* Based on cereal seeds and fresh weight;


Bird Method Body Wt Mean food intake*

Other birds:Grey patridge; Perdix perdix Nagy 1987 381 g 29.5 gGrey patridge; Perdix perdix Croker et al. 02 381 g 50.6 gPheasant; Phasianua colchicus Nagy 1987 953.0 g 58.9Pheasant; Phasianua colchicus Croker et al. 02 953.0 g 102.7* Based on cereal seeds and fresh weight;


Animals Method Body Wt Mean food intake*

All birds: Nagy 1987 343.5 32.9 gCroker et al. 02 343.5 29.2 g

MammalsHarvest mouse, Micromys minutus Nagy 1987 7.0 1.4

Croker et al. 02 7.0 2.3* Based on cereal seeds (fresh weight)

Estimated Daily Intake of a.i. in a small Estimated Daily Intake of a.i. in a small cereal seeds eating bird (b.w. 15 g)*cereal seeds eating bird (b.w. 15 g)*

PDPTAVCBWFIREDI

Estimated daily intake of a.i.:19.3 mg kg bw/dFood intake rate: 5.8 g/day Body weight:15 g.Concentration of a.i. in fresh diet :50 mg/kg Avoidance factor: 1 Fraction of diet obtained in treated area: 1Fraction of food type in diet: 1

* Realistic worst case; based on calculations from Crocker et al.2002

Estimated Daily Intake of a.i. in a small Estimated Daily Intake of a.i. in a small cereal seeds eating mammal (b.w. 25 g)*cereal seeds eating mammal (b.w. 25 g)*

PDPTAVCBWFIREDI

Estimated daily intake of a.i.:11.4 mg kg bw/dFood intake rate: 5.7 g/day Body weight:25 g.Concentration of a.i. in fresh diet :50 mg/kg Avoidance factor: 1 Fraction of diet obtained in treated area: 1Fraction of food type in diet: 1

* Realistic worst case; based on calculation from Crocker et al. 2002

Uncertainty of the estimated food intakeUncertainty of the estimated food intake

Preliminary probabilistic analysis indicated that the upper 95 percentile for the estimate averaged about twice the mean estimate.This result is preliminary, but indicates the potential range of uncertainty.

If the user wished to be precautionary in their assessment, multiplying the estimated food intake by a factor of two might be a reasonable precaution against underestimating food intake.

Expected concentration of a.i. in the Expected concentration of a.i. in the animal after eliminationanimal after elimination

Variable/parameter (unit) Symbol Unit Default

Input:Estimated daily uptake of a compound ETE mg./kg/d

Fraction of daily uptake eliminated (number between 0 and 1)

El

(number between 0 and 1)Output:Expected concentration of active substance in the animal

EC mg./kg

in the animal

)1( ElETEEC

Refinement steps in the evaluation of the Refinement steps in the evaluation of the potential for primary poisoning potential for primary poisoning

As rodenticides inevitably are toxic to non-target species an exposure assessment that is based on exclusive feeding on the bait will always come to the conclusion of potential risk. Two refinement steps are obvious:

Consider accessibility of baits: Accessibility might be reduced by requiring appropriate use

instructions to be put on the label Consider attractivity:

The bait could be unattractive to e.g. birds to a certain degree due to colour, consistency and other factors.

Secondary poisoningSecondary poisoning

Calculation of rodenticide in target animal on Day 1 immediately after first meal

The food intake rate divided with body weight is as default set to 10% i.e. FIR/BW = 0.1

illustrating realistic worst case (AV, PT, and PD = 1) The concentration of a.i. in the bait C = 50 mg/kg

kgmgETE /5111501.0


The estimated residue concentration in target rodent on Day 2 before meal: EC2 = 5 x (1- 0.3) = 3.5 mg/kg

Day 5 after the last meal = 13.9 mg/kg Day 6 * = 9.7 mg/kg Day 7 (mean time to death) = 6.8 mg/kg * The feeding period has been set to a default value of 5 days until the

onset of symptoms after which it eats nothing until its death


For short term exposure the fraction of poisoned rodents in predator´s diet is assumed to be 1.

For long term exposure the fraction of poisoned rodents in predator´s diet is assumed to be 0.5.


Predators (mammals or birds) feeding on poisoned rodents

Oral exposure (PECoral,predator) depends on ECn: Estimated Concentration in rodent on day n ETE: Estimated daily uptake on day n Frodent: Fraction of poisoned rodent in diet of predator

ECn depends on fraction bait consumption

rodentnpredatororal FETEECPEC )(,

Secondary poisoning: Estimated Secondary poisoning: Estimated Concentration in poisoned rodentConcentration in poisoned rodent

0

2

4

6

8

10

12

14

16

18

1 3 5 7 9 11 13Day

Res

idue

s, m

g/kg 20% before

20% after50% before50% after100% before100% after

Refinement steps in the evaluation of the Refinement steps in the evaluation of the potential for secondary poisoning potential for secondary poisoning

If a risk is indicated the following options for refinement are promising:

Evaluate secondary poisoning studies which are already available for current rodenticides

Improve estimate of proportion of target rodent in the diet of predators; suitable information might already be available from literature on feeding ecology; otherwise data could be generated using a marker in the bait

Field studies, monitoring

Conclusions PT 14 RodenticidesConclusions PT 14 Rodenticides Emission Scenario Document has been prepared

(Danish EPA, EUBEES 2) ESD covers use scenarios and environmental

compartments of (presumed) highest concern ESD based on empirical data & default values ESD has not been validated in practice ESD can be used when no other data are

available Applicants should, whenever possible, use

specific data on use pattern and emission rate

Conclusions PT 14 RodenticidesConclusions PT 14 Rodenticides Emission Scenario Document has been prepared

(Danish EPA, EUBEES 2) ESD covers use scenarios and environmental

compartments of (presumed) highest concern ESD based on empirical data & default values ESD has not been validated in practice ESD can be used when no other data are

available Applicants should, whenever possible, use

specific data on use pattern and emission rate

Documents

Emission scenario document for biocides used as rodenticides Jørgen Larsen