Assessing Pesticide Risks to Bees

Transcription

1 U.S. Environmental Protection Agency 1 Assessing Pesticide Risks to Bees Environmental Fate and Effects Division Office of Pesticide Programs January 2015

2 U.S. Environmental Protection Agency 2 Briefing Outline Risk Assessment Process Problem Formulation Exposure Estimates Effects Data Requirements Sublethal Effects Risk Quotients Multiple Lines of Evidence

3 Ecological Risk Assessment Framework 3

4 U.S. Environmental Protection Agency 4 SETAC Global Pellston Workshop 2011 Global Pellston Workshop Representatives of governmental, industry and academia Included representatives of beekeeping industry in Europe and North America 58 participants from 5 continents (North America, Europe, Australia, South America and Africa) Abstract published in Spring 2011 Full proceedings published by Wiley in 2014

5 U.S. Environmental Protection Agency Interim Guidance EPA Interim Guidance on Honey Bee Data Requirements _authors/terrestrial_biology_tech_team/honeybee_data_interim_g uidance.pdf ; Based on SETAC Pellston, EPPO, EFSA guidance. Registrants on notice of additional data under consideration. Ensures consistency in risk assessments

6 U.S. Environmental Protection Agency 6 White Paper and Final Harmonized Guidance 2012: Pollinator Risk Assessment Framework White Paper 2014: Final EPA Guidance on Risk Assessments for Pollinating Bees

7 7 Protection Goals and Assessment Endpoints Establishing the relationship between measurement endpoints and assessment endpoints.

8 U.S. Environmental Protection Agency 8 Risk Assessment Framework Three risk assessment tiers : Tier 1 = screening level assessment (conservative estimates of exposure, risks characterized at individual-level using laboratory data); and, Tiers 2 and 3 = increasing information needs (greater realism, refined estimates of exposure, risk characterized at colony level using field data). Relies largely on guideline studies (and recommends several in development). Focuses on major (and quantifiable) exposure pathways of concern (direct contact, diet). Separate process for foliar vs. soil/seed treatment applications. Decisions consider multiple lines of evidence and uncertainty: Registrant-submitted data, open literature, incident data.

9 U.S. Environmental Protection Agency 9 1. Details of the product and its use pattern Presumption of minimal risk 2a. Is exposure of adult bees a concern? 2b. Is exposure of bee brood a concern? Contact Exposure Oral Exposure Oral Exposure No Tier 1 brood assessment 3a. Calculate Tier 1 screening-level EEC for adult contact exposure 3b. Calculate Tier 1 screening-level EEC for adult oral exposure via pollen and nectar 3c. Calculate Tier 1 screening-level EEC for larval oral exposure via brood food 4a. Calculate Tier 1 screening-level RQs for adult contact exposure (RQ = EEC/adult acute contact LD 50 ) 4b. Calculate Tier 1 screening-level RQs for adult oral exposure (RQ = EEC/adult acute oral LD 50 & RQ = EEC/adult chronic NOAEC)* 4c. Calculate Tier 1 screening-level RQs for larval oral exposure (RQ = EEC/larval acute LD 50 & RQ= EEC/larval chronic NOAEC)* Tier 1 Risk Assessment Scheme for Foliar Spray Application 5 a,b,c. Does any RQ exceed LOC? 6. Refine Tier 1 Exposure Assessment (e.g., using available crop residue studies), Recalculate RQs. Presumption of minimal risk 7 a,b,c. Does any RQ exceed LOC? 9a. Conduct Tier 2 Exposure Studies (e..g, residues in pollen, nectar) 8. Consider Risk Mitigation Options, Uncertainties, Other lines of Evidence; Is a higher tier assessment needed? 9b. Conduct Tier 2 Colony- Level Effect Studies (e..g, semi-field, feeding) Tier Evaluate Tier 2 exposure and colony-level effect results. Consider uncertainties and other lines of evidence. Do results indicate risk? 12. Conduct Tier 3 Field Studies to address uncertainties 11. Consider Risk Mitigation Options, Uncertainties, Other Lines of Evidence; Is a higher Tier assessment needed? Presumption of minimal risk Tier 3 * When tests are sufficiently developed and vetted 13. Evaluate Tier 3 field study results. Consider risk mitigation options, uncertainties and other lines of evidence. Do results indicate risk? Presumption of risk Optional Y N

10 Tier 1 Screening-level Assessment 10

11 U.S. Environmental Protection Agency 11 Recommended Data Guideline Number Special Study (OECD 213) Special Study (OECD 237) Special Study Special Study Special Study (OECD 75) Study Type Honey bee adult acute contact toxicity Honey bee adult acute oral toxicity Honey bee larvae acute oral toxicity Honey bee adult chronic oral toxicity Honey bee larvae chronic oral toxicity Honey bee toxicity of residues on foliage Semi-field testing for pollinators * Field testing for pollinators * Use Pattern Terrestrial Aquatic Forestry Residential Outdoor Greenhouse Indoor Test substance R R R R R NR TGAI R R R R R NR TGAI R CR R R CR NR TGAI R CR R R CR NR TGAI R CR R R CR NR TGAI CR CR CR CR NR NR TEP CR CR CR CR CR NR TEP CR CR CR CR NR NR TEP * May also include studies for quantifying residues in pollen and nectar; R = required ; CR = conditionally required. New bee data shown in red Currently requiring new bee data as special studies, depending on use. Applicable to all pesticides where significant exposure is expected (not just insecticides). Recommend revision of Part 158 data requirements when test guidelines are complete.

12 U.S. Environmental Protection Agency 12 Exposure Estimates (Tier 1) Measurement Endpoint Individual Survival (adults) Individual Survival (adults) Exposure Route Contact Diet Foliar Applications Exposure Estimate* AR English *(2.7 µg a.i./bee) AR Metric *(2.4 µg a.i./bee) AR English *(110 µg a.i /g)*(0.292 g/day) AR Metric *(98 µg a.i /g)*(0.292 g/day) Brood size and success Diet AR English *(110 µg a.i /g)*(0.124 g/day) AR Metric *(98 µg a.i /g)*(0.124 g/day) Soil Treatments Individual Survival (adults) Diet (Briggs EEC)*(0.292 g/day) Brood size and success Diet (Briggs EEC)*(0.124 g/day) Seed Treatments Individual Survival (adults) Diet (1 µg a.i /g)*(0.292 g/day) Brood size and success Diet (1 µg a.i /g)*(0.124 g/day) Tree Trunk Applications ++ Individual Survival (adults) Diet (µg a.i. applied to tree/g of foliage)*(0.292 g/day) Brood size and success Diet (µg a.i. applied to tree/g of foliage)*(0.124 g/day) AR English = application rate in lbs a.i./a; AR Metric = application rate in kg a.i./ha * Based on food consumption rates for larvae (0.124 g/day) and adult (0.292 g/day) worker bees and concentration in pollen and nectar. ++ Note that concentration estimates for tree applications are specific to the type and age of the crop to which the chemical is applied.

13 U.S. Environmental Protection Agency 13 Refined Exposure Estimates Plants Extrapolation from foliar residues Measured residues in pollen/nectar of surrogate crops Measured resides in pollen/nectar of proposed crops Soil Colony Wax Bee bread Honey

14 U.S. Environmental Protection Agency 14 Pollinator Toxicity Testing Laboratory-based studies include: Acute adult (oral, contact); Larval Toxicity Testing through emergence (individual bees); Chronic adult (10-day oral). Semi-field (enclosure) Testing examining whole colony: Effects Brood (eggs, larvae, pupae); Adults (worker, drones, queen). Full-field Testing examining whole colony: More realistic exposure conditions; and, Refined hypothesis testing based on lower-tier studies.

15 U.S. Environmental Protection Agency 15 Tiers II and III: Colony-level Assessment Tier II Semi-field studies Focus on consistency across various levels of biological organization Complementary. At colony level, RQ not formally calculated; Exposure considered within the context of effects on apical endpoints (e.g., impaired survival and reproduction) at the colony level.

16 U.S. Environmental Protection Agency 16 Non-Apis Bees/Insect Pollinators Laboratory-based data on individual bees considered as surrogate for solitary species. Semi- and full-field data on colonies considered as a surrogate for social species. Data on non-apis species considered on a case-by-case basis as a line of evidence in determining extent to which honey bee may not be a reasonable surrogate. Non-Apis test protocols under development (OECD/ICPPR). Challenges to testing non-apis species include: Identifying suitable husbandry conditions; and, Availability of non-apis for standardized testing.

17 U.S. Environmental Protection Agency 17 Risk Quotients Tier 1 only

18 U.S. Environmental Protection Agency 18 Open Literature and Incident Data Used as other lines of evidence in characterizing risk. Open literature studies must be compliant with Evaluation Guidelines for Ecological Toxicity Data in the Open Literature cies_reregistration_workgroup/esa_evaluation_open_literature.htm. Incident data reported in the Incident Data System (IDS) and the Ecological Incident Information System (EIIS) databases: Considered in terms of the certainty index (e.g., probable, highly probable) and legality (e.g., misuse versus registered use); Guidance for Inspecting Alleged Cases of Pesticide-Related Bee Incidents ( e-inspection-guide.pdf) intended to improve quality of incident data.

19 19 Pollinator Toxicity Testing Sublethal effects Behavioral endpoints (grooming; foraging) Histology endpoints (hypopharyngeal gland development) Proboscis Extension Reflex Antennae activity Pheromones/trophallaxis Immunosuppression

20 20 Adverse Outcome Pathways (AOPs) Structure Activity Relationships In vitro Studies In vivo Studies Population Studies/Models Molecular initiating event Key events or predictive relationships spanning levels of biological organization Adverse outcome relevant to risk assessment

21 U.S. Environmental Protection Agency 21 Colony Simulation Model SAP supported use of colony simulation model for assessing effects of pesticides on honey bees. There are no models currently available for regulatory use. Collaborative effort underway to develop model: USDA and EPA (OPP and ORD); Building upon existing USDA model; Field studies will be used to evaluate model; and, Region 5 RARE grant (collaborative effort between Region, ORD, OPP, USDA, PMRA) Potential uses include: Chemical-specific risk assessments; Interpretation of registrant-submitted field studies; Sensitivity analysis of endpoints that are critical to colony survival and productivity; and, Could inform future test development/endpoint selection. 21

22 22 Multiple Lines of Evidence Interpretation of field study within risk assessment will be made in the context of data drawn from lower Tiers Available data taken into account for consistency, coherence, and biological plausibility Available data may include: Tier I laboratory acute/chronic toxicity Open literature Non-target arthropod data Sublethal effects Incident reports Tier II semi-field studies Tier III full field studies Exposure data

23 U.S. Environmental Protection Agency 23 Questions?

24 24 US/Canada and EU Bee Risk Assessment Schemes Attribute General Approach Protection goals Exposure Routes Data Requirements (Honeybee) Data Requirements (non-apis) U.S./Canada Risk Assessment Scheme 3-Tiered Risk Assessment Approach (screening refined) Population size & stability; hive products, biodiversity Oral (pollen, nectar); Contact (spray) Tier 1: Contact & Oral (adult & larvae); Tier 2 (semi-field); Tier 3 (full field) Case-by-Case (special study; protocols not standardized) Trigger values Bee-specific LOC (0.4 acute; 1.0 chronic) Europe Risk Assessment Scheme (EFSA) Same Similar, but more specific goals for honey bees (magnitude and duration of effects) Same oral and contact (spray, dust), but also includes water (guttation, puddle), Same, include some additional endpoints Acute contact & oral; higher tier studies as protocols evolve (bumble bee; solitary bee) Multiple trigger values; safety factors