Stedeford Todd, Zhao Q Jay, Dourson Michael L, Banasik Marek, Hsu Ching-Hung
Integrated Risk Information System, National Center for Environmental Assessment, Office of Research and Development, United States Environmental Protection Agency, Washington, DC, USA.
J Environ Sci Health C Environ Carcinog Ecotoxicol Rev. 2007 Jul-Sep;25(3):245-79. doi: 10.1080/10590500701569430.
The United States Environmental Protection Agency's Integrated Risk Information System (IRIS) includes hazard identification and dose-response assessment values developed by Agency scientists. Uncertainty factors (UFs) are used in the development of IRIS values to address the lack of information in five main areas. The standard UFs account for interspecies uncertainty (UF(A)) and intraspecies variability (UF(H)). The UF(A) addresses uncertainty related to the extrapolation of data from animals to humans, whereas the UF(H) addresses variability amongst individuals (i.e., intrahuman). Additional UFs have been employed to account for database incompleteness, extrapolations from a lowest-observed-adverse-effect level in the absence of a no-observed-adverse-effect level (UF(L)), and subchronic-to-chronic extrapolation (UF(S)). A sixth UF designated as "other uncertainty factors" (UF(O)) has also been applied in place of the UF(L) to account for uncertainty with the adversity of points of departure obtained using benchmark dose modeling. This review will discuss how UF(L), UF(S), and UF(O) have been applied in IRIS assessments, along with the rationale used to describe the choice of UF values that deviate from the standard default of 10.
美国环境保护局的综合风险信息系统（IRIS）包含了该机构科学家制定的危害识别和剂量反应评估值。在制定IRIS值时使用了不确定系数（UFs），以解决五个主要领域信息不足的问题。标准不确定系数考虑了种间不确定性（UF(A)）和种内变异性（UF(H)）。UF(A)解决了从动物数据外推至人类数据的不确定性，而UF(H)解决了个体间（即人类内部）的变异性。还采用了其他不确定系数来考虑数据库的不完整性、在没有未观察到不良反应水平的情况下从最低观察到的不良反应水平进行外推（UF(L)）以及从亚慢性到慢性的外推（UF(S)）。第六个不确定系数指定为“其他不确定系数”（UF(O)），也已被用于替代UF(L)，以考虑使用基准剂量模型获得的出发点不利性的不确定性。本综述将讨论UF(L)、UF(S)和UF(O)在IRIS评估中的应用方式，以及用于描述偏离标准默认值10的不确定系数值选择的基本原理。
