tailieunhanh - Ecological Risk Assessment for Contaminated Sites - Chapter 6

Mô tả đặc tính rủi ro trong các đánh giá Definitive Một người đàn ông khôn ngoan tỷ lệ niềm tin của ông chứng minh. Trong kết luận đó được thành lập trên một kinh nghiệm không thể sai lầm, ông hy vọng sự kiện với mức độ đảm bảo. . Trong trường hợp khác, ông tiến hành thận trọng hơn: ông nặng các thí nghiệm đối diện: ông xem xét bên nào được hỗ trợ bởi số lượng lớn hơn của thí nghiệm: đó bên ông có chiều hướng, với nghi ngờ và do dự, và khi cuối cùng ông. | 6 Risk Characterization in Definitive Assessments A wise man proportions his belief to the evidence. In such conclusions as are founded on an infallible experience he expects the event with the last degree of assurance. . In other cases he proceeds with more caution he weighs the opposite experiments he considers which side is supported by the greater number of experiments to that side he inclines with doubt and hesitation and when at last he fixes his judgement the evidence exceeds not what we properly call probability. D. Hume An Enquiry Concerning Human Understanding Risk characterization for definitive risk assessments consists of integration of the available information about exposure and effects analysis of uncertainty weighing of evidence and presentation of conclusions in a form that is appropriate to the risk manager and stakeholders. The integration of exposure and effects information should be carried out for each line of evidence independently so that the implications of each are explicitly presented. This makes the logic of the assessment clear and allows independent weighing of the evidence. For each line of evidence it is necessary to evaluate the relationship of the measures of effect to the assessment endpoint the quality of the data and the relationship of the exposure metrics in the exposure-response data to the exposure metrics for the site. The actual characterization for ecological risk assessment is then performed by weight of evidence Suter 1993a EPA 1998 . That is rather than simply modeling risks ecological risk assessors examine all available data from chemical analyses toxicity tests biological surveys and biomarkers to estimate the likelihood that significant effects are occurring or will occur and describe the nature magnitude and extent of effects on the designated assessment endpoints. The approach presented in this chapter is based on the assumption that significant effects . effects that could prompt remediation have been .