In complex systems, where multiple stressors interact, many targets are contemporary involved and different health outcomes may be observed, initial assessment efforts have to be addressed to the most relevant scenarios, with the aim of focusing the further risk assessment on the most critical situations (Menzie et al., 2007). This is a “focusing exercise” aimed at guiding assessment efforts and resources towards those scenarios which could correspond to the greatest potential effects on human health.
Typically, at the regional scale different types of environmental and health data may exist for the characterization of the environmental health status. Each chemical stressor (or class of chemical stressors) may be associated, on the basis of available toxicological and/or epidemiological knowledge, to different typologies of diseases identified as possible outcomes of environmental exposure to that chemical.
A “Risk-based Tool for the Regional Ranking of Environmental Chemical Stressors” has been developed by the University of Venice within WP1 activities, with the main aim of support decision-makers in the evaluation of the existing information on environmental contamination and population health status in the region of interest to identify which pairs of “chemical – related health effect” have to be investigated more urgently. Moreover, the tool will allow the identification of priority areas within the considered region, where further assessment should be focused.
The methodology is based on a Weight-of-Evidence approach (Linkov et al., 2009), and in particular on the integration of three types of information, identified as Lines-of-Evidence (LoE), namely:
A set of chemicals is chosen, and the diseases which can be associated to an environmental exposure to these chemicals are identified. Then, for each pair [chemical, disease], the available information for each of the three considered LoE is integrated to obtain a score for each chemical and define a ranking of priority chemicals. Multi-Criteria Decision Analysis (MCDA) has been chosen as the methodological framework allowing the evaluation and integration of data concerning different LoEs, because MCDA supports the choice among multiple alternative based on different criteria and provide a systematic approach for handling different types of information overcoming the limitations of unstructured decision making (Linkov, 2006; Giove et al., 2009).
The methodology adopts a spatial-oriented approach. The spatial dimension of the assessment requires the identification of spatial entities, called Elementary Geographic Units (EGU), representing the smallest geographical level chosen for data aggregation and allowing the comparison and integration of different types of data (they could correspond to administrative units, such as counties or municipalities).
The “Risk-based Tool for the Regional Ranking of Environmental Chemical Stressors” allows the end-user to obtain as possible outputs:
The “Risk-based Tool for the Regional Ranking of Environmental Chemical Stressors” is a software allowing data storage (based on a Microsoft Access database), application of the different methodological phases of the ranking methodology and delivery of results. The tool includes a geo-database linked to a Geographic Information System (G.I.S.) framework for the spatial visualization of results.
The “Risk-based Tool for the Regional Ranking of Environmental Chemical Stressors” will be tested on a Belgian case-study, focused on population exposure to environmental contaminants in the Flemish region, in close collaboration with VITO.
The tool will be freely available on request and the UNIVE research group will support its use and application to further case-studies.
For more info on this topic, please contact: Elisa Giubilato
Giove S., Brancia A. Satterstrom F.K., Linkov I., Decision Support Systems and Environment: Role of MCDA. In Marcomini A., Suter G.W. II, Critto A., (Eds). Decision Support Systems for Risk Based Management of Contaminated Sites. Springer Verlag (2009), New York.
Linkov I., Loney D., Cormier S., Satterstrom F. K., Bridges T., 2009. Weight of Evidence evaluation in environmental assessment: Review of qualitative and quantitative approaches. Science of the Total Environment 407: 5199-5205.
Linkov I., Satterstrom F.K., Kiker G., Batchelor C., Bridges T., Ferguson E., 2006. From comparative risk assessment to multi-criteria decision analysis and adaptive management: recent developments and applications. Environment International 32: 1072-1093.
Menzie C.A., MacDonell M.M., Mumtaz M., 2007. A Phased Approach for Assessing Combined Effects from Multiple Stressors. Environmental Health Perspectives 115 (5): 807-816.