Uncertainty in the design of the measurement frameworks underlying GIS-based human health risk assessment models

GIS-based human health risk assessment (GIS-based HHRA) refers to the integration of GIS with risk assessment modeling for purposes of generating spatially-differentiated risk estimates for specific receptor populations. The use of GIS-based HHRA models allow more representative individual and population risk estimates to be generated due to the explicit consideration for the spatial distribution of chemical concentrations in impacted media as well as the spatial distribution of receptor populations across study areas. Having more representative and spatially-refined estimates of individual and population risk can improve risk-based decision making by decreasing the degree of uncertainty associated with these estimates thereby increasing confidence in the risk-based decisions that are made. Despite the potential of GIS-based HHRA models to enhance environmental and public health decision making, little research has been conducted into the design of these models including the impact that different model designs can have on risk results and risk-based decision making.; Research presented in this dissertation examines this issue of GIS-based HHRA model design and more specifically, the design of the GIS-based measurement frameworks underlying these models. These measurement frameworks are responsible for integrating spatial data coverages and generating spatially-explicit risk estimates for modeled receptor populations. This research demonstrates that, under certain circumstances, the design of the measurement frameworks can significantly impact risk results and the risk-based decisions made using these models. These findings point to the importance of considering measurement framework design uncertainty along with other sources of uncertainty in designing and using GIS-based HHRA models to support environmental decision making. This dissertation research was conducted using five hazardous waste combustion (HWC) test case facilities.