2011 Progress Report: Pesticide Exposure Pathways

EPA Grant Number: R834514C002
Subproject: this is subproject number 002 , established and managed by the Center Director under grant R834514
(EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).

Center: University of Washington Center for Child Environmental Health Risks Research (2010)
Center Director: Faustman, Elaine
Title: Pesticide Exposure Pathways
Investigators: Faustman, Elaine
Institution: University of Washington
EPA Project Officer: Callan, Richard
Project Period: October 1, 2010 through September 24, 2016
Project Period Covered by this Report: August 1, 2010 through July 31,2011
RFA: Children's Environmental Health and Disease Prevention Research Centers (with NIEHS) (2009) RFA Text |  Recipients Lists
Research Category: Children's Health , Health


The Pesticide Exposure Pathways Research Project’s overall aim is to develop a systematic understanding of residential pesticide exposures arising from proximity to agricultural spraying in rural agricultural communities where children live. The proximity exposure pathway is due to transport of pesticides from applied fields to homes and other settings. The mechanisms of transport include spray drift, volatilization, re-suspension and deposition of particles containing pesticides. The pathways project studied both local pesticide application factors and human activity factors that contribute to childhood exposure to pesticides.

Progress Summary:

The highlights of this past year include completing air and particle sampling fieldwork phase I (March – May 2011) and proceeding to phase II (summer of 2011).
In collaboration with the CBPR Project, data were gathered on airborne exposures to organophosphate pesticide dusts and vapors, with the deployment of 46 polyurethane foam passive air samplers and 46 microslide/polypropylene deposition plates in a subset of 21 research participant’s homes, specifically positioned in a living room or kitchen at an average height of 1.5 meters) over a time period of 30 days to collect simultaneous measurements of particle deposition and airborne concentrations of the organophosphorus pesticide chlorpyrifos and its oxon analog. Overall, 95% of these homes agreed to participate in the air monitoring portion of the study. Responding to feedback from the field group, the plan of using 3M Non-Damage Utility Hooks to hang the passive air sampler inside the home was changed to using free-standing ornament hangers for easier location near the deposition plates. Outdoors, a large passive air sampler disk, housed in a stainless steel chamber, was positioned more than 6 meters from the outside of the home at a height of 1.6 to 2.1 meters with these outdoor samplers remaining stable during heavy winds and rain and with no tampering with the instruments noted. In addition to the use of passive air samplers, the fieldwork team also deployed side-by-side active and passive samplers for 7-14 days at two calibration sites in the local communities, a public high school in town (non-proximal), and a weather station near agricultural fields (proximal). Both calibration sites were co-located with Washington State University (WSU) AgWeatherNet stations and Department of Ecology air monitoring sites that record real-time weather data and PM2.5, respectively.
Moreover, a total of 40 MicroDAQ data loggers also were deployed to collect real-time temperature inside and outside the homes. All participant homes were within a 10 miles radius of the nearest WSU AgWeatherNet station, which provided additional real-time data on temperature, precipitation, wind direction, wind speed, and relative humidity.
Finally, to assess the importance of proximity vs potential take-home pathway, researchers used a Global Positioning System (GPS) and identified 8 homes as “proximal/farmworker,” 2 homes as “proximal/non-farmworker,” 6 homes as “non-proximal/non-farmworker,” and 4 homes as “non-proximal/farmworker,” with “proximal” defined as 5 – 200 meters and “non-proximal” as 550 – 1,200 meters of an agricultural field.
Currently, these sampling matrices are being analyzed using liquid chromatography-mass spectrometry (LC-MS-MS) at the University of Washington Environmental Health Laboratory for chlorpyrifos and oxon. In Phase II of the study, these samples will undergo extractions for Azinphos Methyl (AZ) and oxon. Furthermore, the deposition micro slides were analyzed using ImageJ software to count and size dust particles by optical microscopy.

Future Activities:

This information will help researchers describe phase-partitioning of the semi-volatile pesticides and their transformation to the more toxic oxon. In addition, the measured ratios of indoor/outdoor air concentrations will be used to assess infiltration to indoor environments.

Journal Articles:

No journal articles submitted with this report: View all 33 publications for this subproject

Supplemental Keywords:

RFA, Scientific Discipline, Health, INTERNATIONAL COOPERATION, ENVIRONMENTAL MANAGEMENT, Biochemistry, Children's Health, Environmental Policy, Biology, Risk Assessment, pesticide exposure, age-related differences, pesticides, children's vulnerablity, biological markers, agricultural community

Relevant Websites:

http://depts.washington.edu/chc/Exit EPA Disclaimer

Progress and Final Reports:

Original Abstract
  • 2012
  • 2013 Progress Report
  • 2014
  • 2015 Progress Report
  • Final Report

  • Main Center Abstract and Reports:

    R834514    University of Washington Center for Child Environmental Health Risks Research (2010)

    Subprojects under this Center: (EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
    R834514C001 Community-Based Participatory Research
    R834514C002 Pesticide Exposure Pathways
    R834514C003 Molecular Mechanisms
    R834514C004 Genetic Susceptibility