Grantee Research Project Results
Final Report: Pesticide Exposure Pathways
EPA Grant Number: R834514C002Subproject: 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: Center for Air, Climate, and Energy Solutions
Center Director: Robinson, Allen
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
RFA: Children's Environmental Health and Disease Prevention Research Centers (with NIEHS) (2009) RFA Text | Recipients Lists
Research Category: Children's Health , Human Health
Objective:
Specific aims addressed (and referenced publications) between September 25, 2009, and July 31, 2014:
- Determine the dominant transport mechanism for the proximity pathway in a community setting
- Establish the spatial extent of the proximity pathway
- Estimate pesticide residues in the community by combining land-use regression with models of spray drift, volatilization and pest-pressure
- Assess the importance of proximity through land-use regression estimates of exposure
- Monitor indoor/outdoor pesticide levels to assess infiltration into indoor environments
- Assess the relative importance of the take-home vs. proximity pathway
- Evaluate the effect of personal activities on exposures in families living far from applied fields
Specific aims addressed between August 1. 2014, and July 31, 2015:
4. Assess the importance of proximity through land-use regression estimates of exposure
Summary/Accomplishments (Outputs/Outcomes):
Overview
Previously, we have demonstrated elevated concentrations of outdoor chlorpyrifos (CPF) and its more potent transformation product CPF-oxon in outdoor air samples in the Yakima Valley during dormant spray applications periods (Armstrong 2014). These exposures are strongly associated with proximity to crops (pome fruit and stone fruit) using ground applications of CPF. In addition, we have shown that the importance of proximity persists beyond short distances and that living within 2 km of a field is strongly (R2 = 0.55) predictive of outdoor concentrations of CPF and CPF-oxon.
A land-use regression (LUR) exposure model was built to describe the relationship between agricultural land-use characteristics and chlorpyrifos air sampling results from households in the CHC Yakima Valley cohort that were instrumented with PUF-PAS (polyurethane foam passive air sampling) disks (described in previous annual progress reports). Using the instrumented households model, monthly outdoor chlorpyrifos concentrations are now being estimated for non-instrumented households using the same measures of agricultural activity. The exposure model building process and predictions are being prepared for submission to a peer-reviewed journal.
Studies
The study region consisted of approximately 2,000 km2 of mostly rural space with several clusters of residential communities in the Yakima Valley. Agricultural land-use was estimated within 125, 250, 500, 1,000, 2,000, 4,000 and 8,000 meter buffers of study households. Buffer sizes were considered scientifically reasonable due to the volatilization behavior of chlorpyrifos from treated crops and previous pesticide use exposure models. Land use within given buffers was for area of all crops, area of tree fruit orchards, and estimated mass of chlorpyrifos applied during that year. The buffers were then intersected with the field parcel shapefile, which generated polygons that could be summed across crop type for each household. The resulting crop type and area associated with each household was used in conjunction with the pesticide-crop type matrix for chlorpyrifos to estimate the amount of chlorpyrifos use. Measured distances were also available for nearest crop of any type, nearest tree fruit orchard, and elevation.
Results
Summary statistics indicate that among the 181 households in the CHC 3 cohort, 125, 125, and 79 were located within 2,000 meters of cherry, apple, and pear orchards, respectively. Within the same distance, arithmetic mean area (km2) for any crop type was largest for field corn [Mean 1.52 (SD: 1.15)], hops [0.55 (0.87)], and alfalfa hay [0.50 (0.40)]. Among tree fruit, mean area was largest for cherries [0.39 (0.58)], apples [0.32 (0.51)], and pears [0.31 (0.48)]. Preliminary univariate model results confirm our previous finding (Armstrong 2014) that residences proximal to fields experience higher monthly outdoor levels of chlorpyrifos than non-proximal households. The 2,000 and 4,000 meter buffer sizes were found to be most predictive of the relationship between location and outdoor CPF concentration. On average, each 10 meter increase in residential distance from the nearest tree fruit orchard resulted in a 0.09% reduction in geometric mean outdoor CPF air concentration (ng/m3) (95% CI: 0.05, 0.14) (R2 = 0.48). Residential outdoor CPF air concentration was weakly correlated with mass of CPF applied within 250 meters (1.34, 95% CI: 1.10, 1.65, R2 = 0.12), but more strongly correlated with mass applied within 2000 meters (1.008, 95% CI: 1.004, 1.012, R2 = 0.55).
Our PLS LUR model adequately captured (R2 = 0.61) the variability in the 2011 outdoor air concentrations of CPF based on proximity to parcel level crop maps. Component 1 loaded heavily for distance from nearest tree fruit orchard and mass of chlorpyrifos applied within the largest buffers, component 2 loaded heavily for elevation and distance from nearest crop of any type, and component 3 loaded heavily for area of pears and corn within largest buffers. Geographic covariates that were most important for explaining chlorpyrifos variability were related to larger buffers (1-4 km).
Conclusions:
Significance
The discrepancy of larger buffers being more predictive might be attributable to the fact that fewer houses (n = 8) had any chlorpyrifos applied within the smaller buffer compared to the larger buffer (n = 23), but it might also indicate that the off-target movement of airborne chlorpyrifos occurs over greater distances than previously thought. Farmworker status does not appear to be predictive of measured outdoor CPF levels in the full model. Previous significant findings related to farmworker status were likely due to farmworkers living closer to applied fields on average in the sample of homes.
Plans
Journal Articles on this Report : 11 Displayed | Download in RIS Format
Other subproject views: | All 33 publications | 12 publications in selected types | All 11 journal articles |
---|---|---|---|
Other center views: | All 510 publications | 227 publications in selected types | All 178 journal articles |
Type | Citation | ||
---|---|---|---|
|
Armstrong JL, Fenske RA, Yost MG, Galvin K, Tchong-French M, Yu J. Presence of organophosphorus pesticide oxygen analogs in air samples. Atmospheric Environment 2013;66:145-150. |
R834514 (2012) R834514 (2013) R834514 (Final) R834514C002 (Final) |
Exit Exit |
|
Armstrong JL, Fenske RA, Yost MG, Tchong-French M, Yu J. Comparison of polyurethane foam and XAD-2 sampling matrices to measure airborne organophosphorus pesticides and their oxygen analogs in an agricultural community. Chemosphere 2013:92(4):451-457. |
R834514 (2013) R834514 (Final) R834514C002 (Final) |
Exit Exit Exit |
|
Armstrong JL, Fitzpatrick CF, Loftus CT, Yost MG, Tchong-French M, Karr CJ. Development of a unique multi-contaminant air sampling device for a childhood asthma cohort in an agricultural environment. Environmental Science: Processes & Impacts 2013;15(9):1760-1767. |
R834514 (2013) R834514 (Final) R834514C002 (Final) |
Exit Exit |
|
Armstrong JL, Dills RL, Yu J, Yost MG, and Fenske RA. A sensitive LC-MS/MS method for measurement of organophosphorus pesticides and their oxygen analogs in air sampling matrices. Journal of Environmental Science and Health, Part B 2014;49(2):102-108. |
R834514 (Final) R834514C002 (Final) |
Exit |
|
Armstrong JL, Yost MG, Fenske RA. Development of a passive air sampler to measure airborne organophosphorus pesticides and oxygen analogs in an agricultural community. Chemosphere 2014;111:135-143. |
R834514 (Final) R834514C002 (Final) |
Exit Exit Exit |
|
Gibbs JL, Yost MG, Negrete M, Fenske RA. Passive sampling for indoor and outdoor exposures to chlorpyrifos, azinphos-methyl, and oxygen analogs in a rural agricultural community. Environmental Health Perspectives 2017;125(3):333-341. |
R834514 (Final) R834514C002 (Final) |
|
|
Griffith W, Curl CL, Fenske RA, Lu CA, Vigoren EM, Faustman EM. Organophosphate pesticide metabolite levels in pre-school children in an agricultural community:within-and between-child variability in a longitudinal study. Environmental Research 2011;111(6):751-756. |
R834514 (2011) R834514 (2012) R834514 (2013) R834514 (Final) R834514C002 (Final) |
Exit Exit Exit |
|
Jackson JE, Yost MG, Karr CJ, Fitzpatrick C, Lamb BK, Chung S, Chen J, Avise J, Rosenblatt RA, Fenske RA. Public health impacts of climate change in Washington State: projected mortality risks due to heat events and air pollution. Climatic Change 2010;102(1-2):159-186. |
R834514 (2011) R834514 (2012) R834514 (2013) R834514 (Final) R834514C002 (Final) |
Exit |
|
Loftus C, Yost M, Sampson P, Arias G, Torres E, Vasquez VB, Bhatti P, Karr C. Regional PM2.5 and asthma morbidity in an agricultural community: a panel study. Environmental Research 2015;136:505-512. |
R834514 (2015) R834514 (Final) R834514C002 (2015) R834514C002 (Final) |
Exit Exit Exit |
|
Ramaprasad J, Tsai MG, Fenske RA, Faustman EM, Griffith WC, Felsot AS, Elgethun K, Weppner S, Yost MG. Children's inhalation exposure to methamidophos from sprayed potato fields in Washington State:exploring the use of probabilistic modeling of meteorological data in exposure assessment. Journal of Exposure Science and Environmental Epidemiology 2009;19(6):613-623. |
R834514 (Final) R834514C002 (Final) R831709 (2007) |
Exit Exit |
|
Whitely Binder LC, Barcelos JK, Booth DB, Darzen M, Elsner MM, Fenske R, Graham TF, Hamlet AF, Hodges-Howell J, Jackson JE, Karr C, Keys PW, Littell JS, Mantua N, Marlow J, McKenzie D, Robinson-Dorn M, Rosenberg EA, Stockle CO, Vano JA. Preparing for climate change in Washington State. Climatic Change 2010;102(1-2):351-376. |
R834514 (2011) R834514 (2012) R834514 (2013) R834514 (Final) R834514C002 (Final) |
Exit Exit |
Supplemental Keywords:
Risk assessment, pesticide exposure, age-related differences, pesticides, children's vulnerablity, biological markers, agricultural community, RFA, Health, Scientific Discipline, 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 communityProgress and Final Reports:
Original AbstractMain Center Abstract and Reports:
R834514 Center for Air, Climate, and Energy Solutions 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
The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.
Project Research Results
11 journal articles for this subproject
Main Center: R834514
510 publications for this center
178 journal articles for this center