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

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

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

Meridian – St. Luke’sParma Boise – Mt View SchoolNampa - NNUSE Boise – White Pine Monitoring Locations

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)

Air Toxics Study Period FebMarAprMayJunJulAugSepOctNovDecJanFeb 2007 Air Toxics Study Every 6 th Day

Data Quality Assessment – Frequently Detected Species

Data Quality Assessment – Infrequently Detected Species

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

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

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

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.

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).

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

Carcinogenic Risk Drivers Monitoring Site

Communication Management ISDA UI Parma Research Center IDHW EPA

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

Identified Source Categories for Contaminants of Concern Mobile Sources Photo- chemical Production Biomass Burning Geologic/ Wind Erosion Mixed Sources / Stagnation Solvents Agricultural Pesticide Benzene Major Minor Ethyl Benzene Major Minor Formaldehyde Minor Major Minor Acetaldehyde Minor Major Arsenic Minor Major Minor Cadmium Minor Major Manganese Major Methylene Chloride Major 1,3-Dichloropropene Major

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

National Air Toxics Analysis

Mobile

Mobile Source VOCs Mobile

Aldehydes

Geologic/Wind Erosion

(1,3-DCP)

Dispersion Modeling of 40 Acre 1,3 DCP Treatment, 1 st 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/m 2 -s

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

Modeled 1,3 DCP (  g/m 3 ) 40 acre Field 1 st Day Boise Airport meteorology for fall 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.

Modeled 1,3 DCP (  g/m 3 ) 40 acre Field 1 st Day

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

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)

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

Aldehydes