A variety of pesticides have been added to the environment to enhance agricultural production and control pests, weeds, and vector-based diseases. The use of pesticides has led to substantial improvements over the past four decades in the quality and variety of the nation's diet. Also, Iowa's economic well being has been enhanced due to the ability to produce crops efficiently, in part due to use of these pesticides. On the negative side, pesticide use in agriculture has led to their detection in drinking water wells in the state. Many of the pesticides are known to be harmful and present health risks. To assess the human health risks posed by pesticides in Iowa's drinking water supplies, information is needed regarding the spatial extent, magnitude of the contamination and exposed population. Much of the available information on pesticide pollution and human health effects is in the form of tabular summaries and spreadsheets. It is important that this information be compiled into a common format in order to make accurate observations and informed decisions. This research project developed a computer-based prototype system, consisting of a database management system and geographic information system, for recording, processing, and displaying spatial, analytical, environmental, and human exposure data collected in Iowa. The various modules of the system allows the user to enter or retrieve data, prepare standard and ad hoc reports, and generate maps for risk analysis and decision making. A prototype was developed and demonstrated, and can be used for environmental health applications.