Geographic Information Systems for Risk Evaluation: Perspectives on Applications to Environmental Health

Article excerpt

ABSTRACT. Geographic information system (GIS) applications for risk evaluation concerning environmental and ecological health are appearing with greater frequency. In this paper, we devise a conceptual framework for risk evaluation that encompasses and synthesizes several component frameworks (including risk scoping, risk communication, risk assessment (risk analysis), risk management, and risk monitoring) concerning environmental health, and hence human and ecological impacts. The purpose of devising the framework was to understand better where, when, and how GIS might be used for risk evaluation, and to identify gaps in knowledge requiring further research. An examination of 40 publications shows that most of the research done on the use of GIS for risk evaluation concerned applications in risk assessment rather than risk scoping, management, and risk monitoring. A four-level risk assessment framework is proposed, and criteria for evaluating the work are used to clarify what has been accomplished overall and where research opportunities exist. Future directions for the application of GIS in risk evaluation are suggested.

Keywords: risk assessment, GIS, risk analysis, hazardous waste, stakeholder, risk communication

Activities involving potential harm can be said to have some level of risk. Risk is defined as the "probability that a substance or situation will produce harm under specified conditions" (Presidential/Congressional Commission on Risk 1997a). Risk is composed of two factors: the "probability" that an adverse event will occur (e.g., one in one million chance) and the "consequences" (e.g., serious injury, cancer, or death) of the adverse event. In the context of environmental health, risk arises from exposure to hazard. Risk does not exist if exposure to a harmful substance or situation does not occur. Hazard is determined by whether a particular substance or situation has the potential to cause harm to public health and/or the environment. The source of hazard and exposure to hazard have an inherently geographical character about them. Because risk does not occur without exposure, and exposure does not usually occur without coincidence in location and time, geographic information systems (GIS) technology can be very useful in understanding the nature of risk.

GIS applications for risk evaluation within the context of environmental health are appearing with greater frequency. The term "environmental health" covers both human and ecological health. Consequently, risk evaluation involves understanding the nature of risk to which people and other living organisms and their habitats are exposed.

As there are many aspects of risk evaluation cited in literature, e.g., risk scoping, risk communication, risk assessment (risk analysis), risk management, and risk monitoring, we have found it necessary to draw from several conceptual frameworks. Our synthesis, like others, is an attempt to formulate both a broad and a deep perspective as a backdrop for risk-based investigations concerning hazardous waste clean up. U.S. Department of Energy (USDOE) sites are of particular interest because remediation often deals with multiple issues simultaneously. Our discussion of risk evaluation develops mainly from perspectives on human and ecological health risks but recognizes that social and economic concerns are also important (Greenberg 1995) and, hence, does not bar them from consideration.

Because of the complexity of discussions involving risk-oriented hazards and exposures and their management, it is assumed that risk evaluation can benefit from advanced information technology such as GIS. The synergy achievable from the integration of three major information technologies--data management, spatial analysis and computer graphics technologies--encourages the application of GIS in risk evaluation.

GIS technology is a data (information) integration and analysis engine which produces results that can be rendered using map displays at various levels of information resolution (Nyerges 1991). …