Superfund Research Program
A Holistochastic Approach to Human Exposure Assessment
Project Leader: George Christakos
Grant Number: P42ES005948
Funding Period: 1995 - 2006
Researchers have developed rigorous theoretical concepts and tools for the characterization of heterogeneous waste sites. These research findings can be used efficiently for determining regions at risk, reducing uncertainties across broad spatial/temporal scales and assessing the cost of cleanup alternatives. These scientists have emphasized the importance of rigorous scientific approaches and site indicators in establishing the appropriate scale where the site remediation analysis must take place in relation to biological, physicochemical, etc. processes in the region of consideration. The results obtained can be used to study improved exposure models that will lead to better evaluation of the impacts of contaminant sites on the human health and the ecosystem. Proposed contaminant level analysis takes into consideration the contaminant chemistry and the physical heterogeneities of the medium, the hazardous levels determined on the basis of health and regulatory standards, as well as the cost-effectiveness of contaminant site remediation technologies.
Over the past year accurate solutions to porous media flow and transport models were developed using diagrammatic and space transformation techniques. These solutions are significant improvements over existing models and can play a crucial role in the effective implementation of site remedial strategies. A spatiotemporal random field model was also developed that allows the rigorous characterization of space/time variabilities and heterogeneities. This is a significant advancement that provides optimal solutions to spatiotemporal exposure assessment problems. Currently, no other systematic space/time computer codes exist in the literature.