John Leahy, EPA Pesticide Re-evaluation Division

1. John Leahy, EPAPesticide Re-evaluation Division Risk Overview Why Changes are Needed

2. Fumigants Are Applied Many Ways to Control a Variety of Pests 2

3. Focus On Acute Residential Bystander & Occupational Risks Wind Wind blows emissions from an application to a receptor of concern (e.g., house or school) Other types of exposures also considered including: Dietary (methyl bromide only) Drinking water (methyl bromide only) Environmental Community based or ambient exposures in the population 3

4. Risk Assessment Process Hazard Identification Does the agent cause the adverse effect? Dose-Response Assessment What is the relationship between dose and incidence/severity of effects? What exposures are currently experienced or anticipated under different conditions? Exposure Assessment What is the estimated incidence likelihood of the adverse effect in a given population? Risk Characterization

5. Scientific Foundation • Recognized methods used • Public peer review processes under FACA rules • SAB on RfC inhalation risk methodology (1998) • SAP on exposure modeling (2004) • Multi-agency collaboration • USDA • DPR • FDACS • Based on multiple lines of evidence • Hazard data, Monitoring, Modeling, Incidents • Refined as a result of multiple public comment periods

7. Field Emissions (Flux) Monitoring Emissions Are Described As Flux Values (µg/m2/sec) Volatile Residues Cross Section Of Treated Field With Known Surface Area

8. Actual Flux Monitoring Results 430’ 0.072 & ND ppm 430’ - ND & ND ppm 288’ 0.13 & 0.21 ppm 30’ – 0.52 & 0.029 ppm MeBr Field 8 Results 19A; tarped raised bed in CA 200 lb/A; 98/2 MeBr/Pic 12 hr samples; LOD 0.005 ppm 430’ 0.042 & ND ppm 30’ 0.24 & 0.005 ppm 5’ 0.65 & 1.0 ppm 405’ 0.46 & 0.69 ppm 30’ – 0.39 & 0.23 ppm 408’ 0.089 & 0.017 ppm 430’ 0.072 & 0.74 ppm 430’ – 0.028 & 0.65 ppm

9. 30% 25% 20% Flux Rate (% of Application) 15% 10% 5% 0% 0 20 40 60 80 100 120 140 Mean Time Since Application (hours) Example Emissions Profiles

10. Modeling5 Years of Weather Data Used Sources Include*: • National Weather Service (NWS) • FAA’s Automated Surface Observing System (ASOS) • California Irrigation Management Information System (CIMIS) • Florida Automated Weather Network (FAWN) *Data from 6 stations used for analyses including Ventura & Bakersfield CA; Bradenton & Tallahassee FL; Flint MI; Yakima WA

11. PERFUM Model Outputs • Solves for distance at target concentration which is defined by HEC/UF • Uses 5 years of weather data so each analysis would contain 1825 sets of outputs • Tallahassee & Bradenton weather used for southeast region Weather Day 1 Weather Day 2 Treated Field

12. Incident Overview Generally, low frequency of incidents relative to numbers of applications Severe effects occur but low percentage of overall incident rate Reports are consistent with risk assessments based on the nature of effects Major incidents (those involving many people) typically occur because of equipment failure, applicator error, atmospheric conditions Workers tend to have higher incident rates than bystanders “Reconstructing” incidents to examine exact factors which lead to problem can be difficult especially for bystander exposure 12

13. Summary • Peer reviewed methods • Extensive emissions & occupational monitoring data • Also focused on factors which impact emissions • Results indicate risk management required, incident rates are low and effects consistent with risk assessment • Key concern is near applications, buffers reduce those types of exposures • Much ongoing research to evaluate emission controls (e.g., low permeability tarps & soil adjuvants)