Solomon Paul A, Sioutas Constantinos
U.S. Environmental Protection Agency, Office of Research and Development, Las Vegas, NV, USA.
J Air Waste Manag Assoc. 2008 Feb;58(2):164-95. doi: 10.3155/1047-3289.58.2.164.
The U.S. Environmental Protection Agency (EPA) established the Particulate Matter (PM) Supersites Program to provide key stakeholders (government and private sector) with significantly improved information needed to develop effective and efficient strategies for reducing PM on urban and regional scales. All Supersites projects developed and evaluated methods and instruments, and significant advances have been made and applied within these programs to yield new insights to our understanding of PM accumulation in air as well as improved source-receptor relationships. The tested methods include a variety of continuous and semicontinuous instruments typically with a time resolution of an hour or less. These methods often overcome many of the limitations associated with measuring atmospheric PM mass concentrations by daily filter-based methods (e.g., potential positive or negative sampling artifacts). Semicontinuous coarse and ultrafine mass measurement methods also were developed and evaluated. Other semicontinuous monitors tested measured the major components of PM such as nitrate, sulfate, ammonium, organic and elemental carbon, trace elements, and water content of the aerosol as well as methods for other physical properties of PM, such as number concentration, size distribution, and particle density. Particle mass spectrometers, although unlikely to be used in national routine monitoring networks in the foreseeable future because of their complex technical requirements and cost, are mentioned here because of the wealth of new information they provide on the size-resolved chemical composition of atmospheric particles on a near continuous basis. Particle mass spectrometers likely represent the greatest advancement in PM measurement technology during the last decade. The improvements in time resolution achieved by the reported semicontinuous methods have proven to be especially useful in characterizing ambient PM, and are becoming essential in allowing scientists to investigate sources of particulate pollution and to probe into the dynamics and mechanisms of aerosol formation in the atmosphere.
美国环境保护局（EPA）设立了颗粒物（PM）超级站点计划，为主要利益相关者（政府和私营部门）提供显著改进的信息，以制定有效且高效的策略，在城市和区域尺度上减少颗粒物。所有超级站点项目都开发并评估了方法和仪器，并且在这些项目中已取得重大进展并得到应用，从而使我们对空气中颗粒物的积累以及源-受体关系有了新的认识。所测试的方法包括各种连续和半连续仪器，其时间分辨率通常为一小时或更短。这些方法常常克服了许多与基于每日滤膜的方法测量大气颗粒物质量浓度相关的局限性（例如，可能的正或负采样假象）。还开发并评估了半连续的粗颗粒和超细颗粒质量测量方法。所测试的其他半连续监测仪测量了颗粒物的主要成分，如硝酸盐、硫酸盐、铵、有机碳和元素碳、微量元素以及气溶胶的含水量，以及颗粒物其他物理特性的测量方法，如数浓度、粒径分布和颗粒密度。颗粒质谱仪尽管由于其复杂的技术要求和成本，在可预见的未来不太可能用于国家常规监测网络，但在此提及是因为它们能近乎连续地提供有关大气颗粒按粒径分辨的化学成分的大量新信息。颗粒质谱仪可能代表了过去十年中颗粒物测量技术的最大进步。所报道的半连续方法在时间分辨率上的改进已证明在表征环境颗粒物方面特别有用，并且对于科学家研究颗粒物污染的来源以及探究大气中气溶胶形成的动力学和机制变得至关重要。
