Revised Cumulative Risk Assessment: Organophosphorus Pesticides

1. Revised Cumulative Risk Assessment: Organophosphorus Pesticides Office of Pesticide Programs June 18, 2002

2. Welcome Lois Rossi, Director Special Review and Reregistration Division

3. Managing Risk From Organophosphorus Pesticides

4. Outline of Presentation • Plan for the OPs • Progress to date • Achievements in: • Risk reduction • Methods development • Process improvements

5. Plan for the OPs • Several OP Reregistration Eligibility Decisions completed before August 1996 • After August 1996 OPs became a major focus of Reregistration and Tolerance Reassessment • In the last six years a tremendous amount of resources dedicated to: • Risk assessment and risk management of the individual OP chemicals • Developing cumulative risk assessment methods and applying them to the OPs • It is appropriate to examine the results and the achievements of the last six years

6. Implementation of the Plan • Refine available exposure methods and data • Develop a public process to allow greater stakeholder access to information and to facilitate input on: • Science policies • Exposure data and assumptions • Risk assessments • Risk management • Develop methods for aggregate risk assessment • Develop methods for cumulative risk assessment

7. Status of OPs • 49 total OPs ever registered • 7 cancelled before 1996 • Chlorfenvinphos, Chlorthiophos, Dialifor, Dioxathion, Monocrotophos, Phosphamidon, Sulprofos • 42 started the public participation process

8. Status of OPs (continued) • 3 early voluntary cancellations • Fonofos, Isazophos, Isofenphos • 5 recent cancellations • Chlorpyrifos methyl, Ethion, Ethyl parathion, Fenamiphos, Sulfotepp • 34 OPs remain

9. Status of Tolerance Reassessment FQPA: Must reassess all tolerances by Aug. 2006 • 33% by August 3, 1999 • Completed! • Goal 3208, 3290 actually reassessed • 66% by August 3, 2002 • On track for completing goal of 6416 • 100% by August 3, 2006 • Final goal: 9721

10. Status of OP Tolerance Reassessment • 1691 at the start of FQPA (1996) • 17.4% of all tolerances (9721) • 871 reassessed through revocation or other process • 98 reassessment underway (revocation) • 722 OP tolerances remain to be reassessed

11. Public Participation Process • Phase 1 -- Registrant "Error Only" Review (30 days)  • Phase 2 -- EPA Considers Registrants Comments (up to 30 days) • Phase 3 -- Public Comment on Prel. Risk Asmt. (60 days)   • Phase 4 -- EPA Revises Risk Assessments; Technical Briefing (up to 90 days)  • Phase 5 -- EPA Solicits Risk Mgmt. Ideas (60 days) • Phase 6 -- EPA Develops Risk Mgmt. Strategies (60 days)

12. Public Participation Process Individual Reregistration Eligibility Decisions (IREDs) • 39 preliminary risk assessments -- public comment • 39 revised risk assessments B public comment • 32 IREDs/TREDS • Communication about each OP: overviews, summaries, fact sheets, comment responses • Conference calls and closure calls • 18 Technical Briefings • Stakeholder meetings B 3 outside DC

13. Public Participation Process (continued) TRAC & CARAT (Advisory Committees) • 10 TRAC and 3 CARAT meetings • Numerous TRAC and CARAT Workgroup meetings • 50+ TRAC/CARAT staff papers

14. Public Participation Process (continued) Development of Cumulative Assessment • 5 Technical Briefings • Drinking Water Methodology Workshop • Numerous Science Advisory Panel meetings • Preliminary assessment B public comment • The release of the revised assessment

15. Achievements in Risk Reduction - Residential - • Residential use reduced by >20 million pounds annually • Principally as the result of risk mitigation for chlorpyrifos and diazinon

16. Residential (continued) Universe of chemicals • Started with 17 OPs with residential/public area uses • 7 OPs excluded from cumulative assessment because residential uses were eliminated/reduced to a negligible level (e.g. limited to bait stations, fire ant mounds) • Of the remaining 10, two are limited to public health uses (naled, fenthion) • 3 OPs with residential/public area uses still under review (DDVP, malathion, tetrachlorvinphos)

17. Residential (continued) Indoor Uses • Initially 9 OPs had indoor uses • Now only DDVP • Initially 6 OPs had pet uses – now only tetrachlorvinphos and DDVP • Indoor use of chlorpyrifos, fenitrothion, and trichlorfon limited to pre-packaged child-resistant bait stations (negligible exposure)

18. Residential (continued) Protecting Public Health Uses • Public Health uses retained where individual assessments indicate no risks of concern • Chlorpyrifos fire ant mound treatment • Chlorpyrifos mosquito control • Fenthion mosquito control • Naled mosquito and black fly control • Phosmet fire ant mound treatment

19. Residential (continued) • For the cumulative assessment: • Used daily residential estimates in probabilistic assessment for the first time • developed regional assessments to cover spatial variation throughout the U.S. • These advances together will likely have a major impact on future residential risk assessment methodology

20. Achievements in Risk Reduction- Food - • Many chemicals faced a much higher standard as the result of the FQPA safety factor requirement • This together with generally very low toxicological endpoints for cholinesterase inhibition resulted in extremely low allowable exposures for most chemicals • EPA & USDA increased PDP monitoring of OP residues on foods highly consumed by children • Agency quickly implemented use of probabilistic dietary exposure estimates on a routine basis

21. Food (continued) • Most OPs met these very high standards • When dietary risks of concern were identified, risks were mitigated: • Use removed from OP/crop combination • Use pattern changes • e.g., rate, frequency, timing

22. Food (continued) • Used rigorous methods and high quality data and worked with stakeholders on viable use pattern changes: • Addressed dietary risks of concern • Limited disruption to agriculture

23. Achievements in Risk Reduction- Drinking Water - • OPP now routinely addressing drinking water risks • Surface water models enhanced to include a scenario representative of a drinking water reservoir • Screening level model developed for groundwater • Agency moved on several fronts to obtain improved water monitoring data and is continuing that work • Effects of drinking water treatment beginning to be addressed

24. Drinking Water (continued) • OPs are not a major concern for drinking water (relative to some other classes of chemicals) • Time generally allowed for data development when concerns were identified • Drinking water risks were mitigated through: • Use removed from certain OP/crop combinations • Use pattern changes • e.g., rate, frequency, timing, use area

25. Drinking Water (continued) • For the cumulative assessment: • Used daily drinking water estimates in probabilistic assessment for the first time • Developed regional assessments to cover spatial variation throughout the U.S. • These advances together with improved modeling and monitoring likely to have a major impact on future drinking water risk assessment methodology

26. Achievements in Risk Reduction- Worker Risk - • Worker risks are important concern for Ops • Very low toxicological endpoints for cholinesterase inhibition often resulted in very low exposures presenting risks of concern • Risk/Benefit balancing required an enormous amount of input from stakeholders

27. Worker Risk (continued) Agency worked quickly to complete review of ARTF data • Excellent source of extensive, up-to-date data on exposure of re-entry workers • Allowed exposures for specific tasks to be calculated separately PR notice AWorker Risk Mitigation for Organophosphate Pesticides@ • Focused stakeholder attention on worker risks • Leveled playing field by stating EPA’s approach

28. Worker Risk (continued) • Most chemicals showed some worker risks of concern (handler and/or re-entry) • Two chemicals cancelled in large part due to worker risk: • Mevinphos (1994) • Ethyl parathion (last use date 10/31/03)

29. Worker Risk (continued) Handler risks addressed in several ways: • Closed mixing loading systems applied to many chemicals/scenarios • Closed cabs with various levels of respiratory protection applied to many chemicals/scenarios • Maximum PPE used in some cases where closed systems not feasible

30. Worker Risk (continued) • Most hand held application methods eliminated • Certain formulation types (e.g. dusts) eliminated or restricted • Reductions in amount handled • Reduced rates/frequency of application • Some restrictions on amounts used when mixer/loader/applicator is same person • Some restrictions on aerial applications

31. Worker Risk (continued) Re-entry risks addressed in several ways: • Tailored to specific problem • Significant input from stakeholders • Creative solutions in toughest cases (high risks, high benefits), collecting bio-monitoring and will reexamine risks

32. Achievements in Risk Reduction- Ecological Risk - Many risk management actions described above also address ecological risks • Chlorpyrifos and diazinon mitigation • Azinphos methyl: eliminated use on sugarcane and cotton in large part due to aquatic concerns • Decreased rates/application frequency; limited area covered (e.g. on golf courses, change from broadcast to spot treatments)

33. Ecological Risks (continued) Other risk mitigation methods utilized: • Watering in/incorporation of granules • Altered timing of applications to reduce exposure to wildlife at most vulnerable times (e.g. nesting) • Developed new disposal methods for cattle dip vats (coumaphos) • Buffer zones (for spray drift) • Addressed special risk concerns (e.g. honey bees) • Addressed special habitat concerns (fenthion) • Improved labeling (e.g. emphasize best management practices)

34. Summary • Major accomplishment in which many people played an important role • Better results when people work together • Establishment of an effective public participation process ensures the continuation of a productive working relationship

35. Science Assessment Staff from the Health Effects Division and Environmental Fate and Effects Division

36. General Overview and Introduction Randolph Perfetti, Ph.D Associate Director, Health Effects

37. Roadmap • Background • Activities Since the Preliminary Assessment • Major Revisions in This Assessment • Highlights of Sensitivity Analyses

38. Background • FQPA 1996 requirements • Methods development • SAP reviews and public comments, technical briefings • Development of Preliminary Assessment • Revised Assessment

39. What is this Cumulative Assessment • Multiple chemicals with common mechanism of toxicity • Multiple routes of exposure • Multiple pathways of exposure

40. Roadmap • Background • Activities Since the Preliminary Assessment • Major Revisions in This Assessment • Highlights of Sensitivity Analyses

41. Activities Since Preliminary Assessment • Addressed the FQPA Safety Factor • Incorporation of new food processing factors • Sensitivity analyses • SAP review • Public comments and technical briefing

42. Roadmap • Background • Activities Since the Preliminary Assessment • Major Revisions in This Assessment • Highlights of Sensitivity Analyses

43. Major Differences • Hazard/ Dose Response • Relative Potency Factors • FQPA Factors • Food Exposure • New processing factors • Over- tolerance residues • Time frames • Populations Considered

44. Major Differences • Water • Number of regions • Populations considered in Region A • Residential • Number of regions • Distributions used • Populations considered in Region A • Pet uses

45. Major Differences • Regional • Preliminary OP CRA – 13 regions • Revised OP CRA – 7 regions • 7 regions effectively describes geographical/climatological differences

46. Preliminary Regional Framework Source: USDA ERS

47. Revised Regional Framework Region A

48. Regional Integrated Output

49. Risk Characterization • Summarizes and integrates all of the information from the various components of the assessment. • Looks at: • Strengths and weaknesses of the data used including any potential biases in input parameters and the direction of that bias, • Reliability and availability of the data, as well as the characteristics of the exposure models, and attempts to bound that uncertainty. • The revised assessment discusses in great detail what data have been used; how the data have been used; and the strengths and weaknesses of the resulting analysis.

50. Roadmap • Background • Activities Since the Preliminary Assessment • Major Revisions in This Assessment • Highlights of Sensitivity Analyses