GIS-EpiLink: a spatial search tool for linking environmental and health data.

One inherent characteristic of both environmental data and health data is that they have a location component. This characteristic makes Geographic Information Systems (GIS) an ideal and sometimes indispensable tool for analyzing environmental and health data. Indeed, the past decade witnessed significant efforts in developing GIS tools for supporting epidemiologic research. Despite these efforts, the availability of accessible GIS tools that can be easily used by epidemiologists to link environmental and health data has remained a problem. We present a simple spatial search tool--GIS-EpiLink--that can be used to link environmental and health data when distance between an environmental site and the location of the maternal address of a case or control is used as a proxy for exposure. The tool was used in a research project and it successfully provided the necessary data for epidemiological analyses. This tool should be very useful to epidemiologists in environmental health research.