APPENDIX D BACKGROUND ON RISK ASSESSMENT FOR SCREEN RECLAMATION PROCESSES: SCREEN

combination with a hazard narrative, to characterize a chemical's human carcinogenic potential- rather than the classification system described above. D-1 HUMAN HEALTH RISK Assessment of the human health risks presented by chemical substances includes the following components of analysis: Hazard Identification is the process of determining whether exposure to a chemical can cause an adverse health effect and whether the adverse health effect is likely to occur in humans. Dose-response Assessment is the process of defining the relationship between the dose of a chemical received and the incidence of adverse health effects in the exposed population. From the quantitative dose-response relationship, toxicity values are derived that are used in the risk characterization step to estimate the likelihood of adverse effects occurring in humans at different exposure levels. Exposure Assessment identifies populations exposed to a chemical, describes thei