Esmen N A, Marsh G M
University of Oklahoma, Health Sciences Center, Oklahoma City 73190, USA.
J Expo Anal Environ Epidemiol. 1996 Jul-Sep;6(3):339-53.
In epidemiological investigations, when the estimation of integrated exposures over long time intervals covering years or decades is required, the quantitative assignment of exposure levels by simplistic models may prove to be inadequate for most applications. This difficulty may be partially addressed by modifying the mathematical models used for the prediction of dispersions of emissions from pollution sources. A theoretical model based on the atmospheric dispersion of contaminants is proposed. While the development of the theoretical model is straightforward, the data requirements in the application of the model may impose some limitations. The methods developed to resolve or alleviate these limitations suggest that many currently used environmental exposure assignment techniques may be too crude to be of value; even the more sophisticated method proposed can only be used with some reservations. Although several difficulties associated with environmental exposure estimation remain unresolved, the careful and rigorous analysis of the available data and the application of the method suggested here can reduce the exposure misclassification errors to acceptable levels. The quantitative estimations of the limitations are based on estimation procedures and aerometric data used in a hilly terrain, and thus should represent testing of the method under an extreme condition.
在流行病学调查中，当需要估算长达数年或数十年的长期综合暴露量时，对于大多数应用而言，使用简单模型对暴露水平进行定量赋值可能并不充分。通过修改用于预测污染源排放扩散的数学模型，这一难题或许能得到部分解决。本文提出了一种基于污染物大气扩散的理论模型。虽然该理论模型的构建较为直接，但模型应用中的数据要求可能会带来一些限制。为解决或缓解这些限制而开发的方法表明，许多当前使用的环境暴露赋值技术可能过于粗糙，毫无价值；即便所提出的更为复杂的方法也只能谨慎使用。尽管与环境暴露估算相关的若干难题仍未得到解决，但对现有数据进行仔细严谨的分析，并应用本文所建议的方法，可将暴露误分类误差降低至可接受水平。对这些限制的定量估算是基于在山区地形中使用的估算程序和气象数据，因此应代表在极端条件下对该方法的测试。
