A Mass Balance Framework for Assessing Flows of Environmental Pollutants: Application to Lead as a Case Study

城市人口暴露在各种各样的环境污染物中。为了制定尽量减少接触的战略，有必要了解污染物从其来源转移到最终汇的过程。该项目将提高我们对所涉及的关键过程的理解，并将开发评估污染物流动的工具，重点关注洛杉矶盆地的铅元素。总体目标有三个。首先，将查明涉及铅排放以及含铅颗粒的沉积和再悬浮的过程。这将通过收集几年来空气中铅浓度的现有信息，并通过对已实现的过滤器进行铅特性测量来实现。目前研究的结果，研究沉积和再悬浮颗粒从表面将应用。其次，将开发一个改进的质量平衡模型，可用于确定铅的主要来源类别和汇。将确定减少空气中铅浓度的可能控制策略。该项目的这一部分将利用现有的质量平衡模型，并将根据敏感性分析和工程近似的使用对其进行修改和评估。第三，该项目将包括根据对铅源和铅汇的了解、人类接触的估计减少量和减少成本，确定几种控制策略中每种策略的净效益。总的来说，该项目的结果将有助于我们了解影响人类接触环境污染物的因素，并将有助于制定减少接触的控制战略。

Urban populations are exposed to a variety of environmental pollutants. To develop strategies for minimizing exposure, it is necessary to understand the processes by which pollutants are transported from their sources to eventual sinks. This project will improve our understanding of the key processes involved and will develop tools for assessing pollutant flows, focusing on the element lead in the Los Angeles Basin. There are three general goals. First, processes involving emissions of lead, as well as deposition and resuspension of lead-containing particles, will be identified. This will be achieved by gathering existing information on airborne lead concentrations over several years and by conducting measurements of lead characteristic on achived filters. Results of current research investigating deposition and resuspension of particles from surfaces will be applied. Second, an improved mass balance model will be developed that can be used to identify key source categories and sinks of lead. Possible control strategies for reducing airborne concentrations of lead will be identified. This part of the project will make use of existing mass balance models, which will be modified and evaluated based on sensitivity analyses and use of engineering approximations. Third, the project will include determination of the net benefits of each of several control strategies based on knowledge of lead sources and sinks, estimated reductions in human exposure, and costs of abatement. Overall, the results of this project will help our understanding of factors influencing human exposure to environmental pollutants and will assist in developing control strategies to reduce exposure.