A conceptual model outline for integrated exposure assessment of waste disposal sites

There are generic elements in environmental risk assessments, which are independent of the subject to which risk analysis is applied. Examples of these elements are as follows: baseline study, hazard identification, hazards' concentration assessment, risk quantification, etc. Another important example of such generic elements is exposure assessment, which is required in a risk analysis process for landfill leachate as it would in any other environmental risk issue. Furthermore, computer models are also being developed to assist risk analysis in different fields. However, in the literature review of risk assessment approaches in general and risk analysis regarding landfills in particular, it was discovered that a comprehensive risk assessment methodology addressing all relevant modules and submodules for landfill leachate does not exist. A range of knowledge deficiencies and models' limitations has been uncovered in the literature reviewed to date. One of which is the absence of a holistic exposure assessment framework aided with a corresponding computer model specifically for quantitative risk analysis of landfill leachate. The same is the case for landfill gas and degraded landfill waste (although both are not the focus of this article). From the perspective of landfill leachate, this article attempts to outline an integrated and holistic framework of the exposure assessment accompanied with a computer model, thereby bridging knowledge gaps