Zartarian V G, Ott W R, Duan N
Civil and Environmental Engineering Department, Stanford University, California 94305-4020, USA.
J Expo Anal Environ Epidemiol. 1997 Oct-Dec;7(4):411-37.
This paper develops a unified theoretical framework for understanding exposure to environmental pollutants and other agents. It reviews the scientific literature to describe the many diverse and often confusing ways in which the term "exposure" is being used. Using six criteria proposed for a useful framework, a set of quantitative definitions, which encompass and expand upon existing definitions, is developed. After "agent" (e.g., a pollutant) and "target" (e.g., a person's hand) are defined, "exposure" is defined as the contact between an agent and a target. An "instantaneous point exposure" is defined as the joint occurrence of two events: 1) point i of a target is located at (xi, yi, zi) at time t, and 2) an agent of concentration Ci is present at location (xi, yi, zi) at time t. It is shown that the definition of instantaneous point exposure is fundamental in that all other functions of exposure with respect to space or time-such as the average exposure and the integrated exposure-can be derived from it. Because exposure and dose are closely related and often confused, our framework also includes a general definition of dose that is consistent with common usage. Finally, the definitions in this unified theoretical framework are shown to apply to inhalation exposure, dermal exposure, and ingestion exposure. In addition to the literature review and the quantitative definitions of exposure, this paper includes a glossary of terms that are proposed to help establish a common language for the exposure sciences.
本文建立了一个统一的理论框架，用于理解对环境污染物及其他介质的暴露。它回顾了科学文献，以描述“暴露”一词被使用的多种不同且常常令人困惑的方式。利用为一个有用框架提出的六个标准，开发了一组定量定义，这些定义涵盖并扩展了现有定义。在定义了“介质”（如污染物）和“靶标”（如人的手）之后，“暴露”被定义为介质与靶标之间的接触。“瞬时点暴露”被定义为两个事件的同时发生：1）靶标的点i在时间t位于(xi, yi, zi)，以及2）浓度为Ci的介质在时间t存在于位置(xi, yi, zi)。结果表明，瞬时点暴露的定义是基础的，因为关于空间或时间的所有其他暴露函数——如平均暴露和累积暴露——都可以从它推导出来。由于暴露和剂量密切相关且常常被混淆，我们的框架还包括一个与常用用法一致的剂量的一般定义。最后，这个统一理论框架中的定义被证明适用于吸入暴露、皮肤暴露和摄入暴露。除了文献综述和暴露的定量定义外，本文还包括一个术语表，旨在帮助建立暴露科学的通用语言。
