Western Region Pesticide Meeting Air Monitoring Studies for Agriculture-Urban Interfaces

1. Western Region Pesticide Meeting Air Monitoring Studies for Agriculture-Urban Interfaces Carl A. Brown, Ph.D. Idaho Department of Environmental Quality

2. Outline Purpose of study Background/Description of sites Preliminary Risk Screening Analysis Source identification 1, 3-DCP Wrap-up

3. Treasure Valley Air Toxics Study • EPA Community Scale Air Toxics Monitoring Project • Goals: • Understand spatial and seasonal trends of air toxics in the Treasure Valley • Identify source categories • Number of individual contributors

5. Monitoring Locations Meridian – St. Luke’s Parma Boise – Mt View School Nampa - NNU SE Boise – White Pine

7. Sampling and Analysis Methods • Metal/Trace Element Hazardous Air Pollutants • Quartz PM10 Hi-vol filters • Metals analysis by EPA IO-3.5 (ICP analysis) • Volatile Organic Carbon Compounds (VOCs) • Whole-air samples in evacuated Summa Cans • EPA Method 15A (GC/FID) • Carbonyls (aldehydes and ketones) • Sample adsorbed on DNPH cartridge • Analysis by EPA Method 11A (HPLC)

8. Air Toxics Study Period Every 6th Day

9. Data Quality Assessment – Frequently Detected Species

10. Data Quality Assessment – Infrequently Detected Species

11. What is 1, 3 DCP? • Soil fumigant used mainly to control nematodes • Onions • Potatoes • Sugar beets • Trade name Telone marketed exclusively by Dow • State specific rules in CA limiting its use • Based on EPA pesticide renewal process a number of BMP have been implemented

12. Data Quality Assessment • % > MRL • Precision • Completeness • In order to characterize a pollutant… you need to first detect it…

13. Risk Screening Process Remove species with low data quality Determine maximum measured concentration Compare maximum concentration to conservative benchmarks

14. Risk Screening Process • Compare to conservative benchmarks: Non-carcinogens • Hazard quotient > 0.1: • The ratio of the potential exposure to a substance and the level at which no adverse effects are expected.

15. Risk Screening Process Compare to conservative benchmarks: Carcinogens 1 in a Million Cancer Risk: A risk level of 1 in a million implies a likelihood that 1 person, out of a population of one million equally exposed people would contract cancer if exposed continuously (24 hours per day) to the specific concentration over 70 years (an assumed lifetime).

16. Risk Screening After removing the compounds measured with a low confidence, the following species are the remaining contaminants of concern: • acetaldehyde • arsenic • benzene • cadmium • (cis- and trans-)1,3-dichloropropene • ethyl benzene • formaldehyde • manganese • methylene chloride

17. Carcinogenic Risk DriversMonitoring Site

18. Communication • Management • ISDA • UI Parma Research Center • IDHW • EPA

19. Source Identification Methods • Statistical “Receptor Modeling” methods • Principal Component Analysis – PCA • Positive Matrix Factorization – PMF • Temporal patterns • Correlations with other species/tracers • Seasonal-spatial trends • Experience with typical source categories • Other studies/literature • Source investigation

20. Identified Source Categoriesfor Contaminants of Concern

21. Data Comparisons • NATA: National Air Toxics Assessment • NATA provides inhalation cancer and non-cancer risks at the county and census tract level • Comparison to national monitoring data

22. National Air Toxics Analysis

24. Mobile

25. Mobile

26. Mobile Mobile Source VOCs

27. Aldehydes

28. Aldehydes

29. Geologic/Wind Erosion

30. Geologic/Wind Erosion

31. (1,3-DCP)

32. (1,3-DCP)

35. Dispersion Modeling of 40 Acre 1,3 DCP Treatment, 1st 24-hours • Industrial Source Complex Area Source Model • Fall meteorology for Treasure Valley, Idaho • 1,3 DCP application rate: 177 lb/acre • Application Acreage: 40 acres • Total 1,3 DCP Flux (cis + trans) based on peak 24-hour loss of 7% of applied DCP: 1.62e-05 gm/m2-s

36. 1,3 DCP Peak Flux, 7% loss in 1st 24-hrs

37. Modeled 1,3 DCP (g/m3) 40 acre Field 1st Day • Boise Airport meteorology for fall 2007. • Concentrations represent the highest 1 day total DCP concentration. • Peak concentration near the field is 367 ug/m3. • The maximum contour ridge extending toward the NW represents nighttime drainage wind directions when the air is stable.

38. Modeled 1,3 DCP (g/m3) 40 acre Field 1st Day

41. Modeled DCP concentration/distance • For Parma, the observations and model results are consistent for a 40 acre field about 200m to 2500m ( 1/8 to 1.5 miles away). • For NNU, the observations and the model results are consistent for a range of about 7500 to 9500 meters (or 4.6 to 6 miles away) approximately the distance from NNU to the agricultural areas surrounding Nampa. • Could be multiple fields at greater distances • Model results are reasonably consistent with the measurements

42. What about human health risk? • Conference call with pesticide risk assessor with EPA • 1, 3 DCP concentrations in the range of what EPA would have expected for rural/agricultural area and not a human health concern • Health Consultation with Dr. Kai Elgethun (IDHW)

43. Summary • Monitored air toxics at 5 sites across the Treasure Valley • Source attribution/risk screening • Most species at or below national median • 1, 3-DCP

44. Aldehydes