| Identifying Populations Potentially Exposed to Agricultural Pesticides Using Remote Sensing and a Geographic Information System Mary H. Ward,1 John R. Nuckols,2 Stephanie J. Weigel,2 Susan K. Maxwell,3 Kenneth P. Cantor,1 and Ryan S. Miller2 1Occupational Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, Maryland, USA
2Environmental Health Advanced Systems Laboratory, Department of Environmental Health, Colorado State University, Fort Collins, Colorado, USA
3Raytheon, EROS Data Center, Sioux Falls, South Dakota, USA Abstract
Pesticides used in agriculture may cause adverse health effects among the population living near agricultural areas. However, identifying the populations most likely to be exposed is difficult. We conducted a feasibility study to determine whether satellite imagery could be used to reconstruct historical crop patterns. We used historical Farm Service Agency records as a source of ground reference data to classify a late summer 1984 satellite image into crop species in a three-county area in south central Nebraska. Residences from a population-based epidemiologic study of non-Hodgkin lymphoma were located on the crop maps using a geographic information system (GIS) . Corn, soybeans, sorghum, and alfalfa were the major crops grown in the study area. Eighty-five percent of residences could be located, and of these 22% had one of the four major crops within 500 m of the residence, an intermediate distance for the range of drift effects from pesticides applied in agriculture. We determined the proximity of residences to specific crop species and calculated crop-specific probabilities of pesticide use based on available data. This feasibility study demonstrated that remote sensing data and historical records on crop location can be used to create historical crop maps. The crop pesticides that were likely to have been applied can be estimated when information about crop-specific pesticide use is available. Using a GIS, zones of potential exposure to agricultural pesticides and proximity measures can be determined for residences in a study. Key words: agriculture, epidemiology, exposure assessment, geographic information systems, pesticides, remote sensing. Environ Health Perspect 108:5-12 (2000) . [Online 22 November 1999] http://ehpnet1.niehs.nih.gov/docs/2000/108p5-12ward/ abstract.html Address correspondence to J.R. Nuckols, Colorado State University, 147 Environmental Health Building, Fort Collins, CO 80523-1676 USA. Telephone: (970) 491-7295. Fax: (970) 491-2940. E-mail: jnuckols@cvmbs.colostate.edu We acknowledge the support and cooperation of the Nebraska State Farm Service Agency (M. Bowen, Director) and of all of the individual county agencies and their staffs who helped with the ground reference information, especially B. McDermott and the Hall County Farm Service Agency staff. This project was partly made possible through the support of the National Cancer Institute subcontract NO2-CP-71100. Received 29 July 1998 ; accepted 14 July 1999.
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