Measuring and modeling mercury in the atmosphere: a critical review
Measuring and modeling mercury in the atmosphere: a critical review
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DOI：
10.5194/acp-15-5697-2015
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发表时间：
2015-01-01
影响因子：
6.3
通讯作者：
Heidecorn, K.
中科院分区：
文献类型：
--
作者：
Gustin, M. S.;Amos, H. M.;Heidecorn, K.
汞（Hg）是一个全球性的健康问题，由于其毒性和普遍存在于环境中。在这里，我们审查目前的方法来测量汞在大气中的形式和用于解释这些数据的模型。大气汞有三种操作定义的形式：气态元素汞（GEM）、气态氧化汞（GOM）和颗粒结合汞（PBM）。GEM测量（在金表面上收集）具有相对的可信度，但GOM（在氯化钾（KCl）涂层的扩散管上收集）和PBM（使用各种方法收集）的了解较少。现场和实验室调查表明，测量GOM和PBM的方法受到随环境设置而变化的分析干扰的影响（例如，臭氧、相对湿度）和由KCl涂覆的扩散管测量的GOM浓度可能太低，根据GOM的化学组成，低1.6至12倍。GOM的组成（例如，HgBr 2、HgCl 2、HgBrOH）在空间和时间上变化。这对改进现有的测量方法和开发新的方法、模型/测量比较、模型开发和评估趋势具有重要意义。以前公布的数据的不明确的特点，现在可以重新审查，并可能解释，这是通过案例研究证明。未来研究的优先事项包括识别环境空气中的GOM化合物，并开发有关其化学和物理特性以及GOM和PBM校准系统的信息。有了这些信息，可以开发氧化还原机制和相关速率系数的识别。
Mercury (Hg) is a global health concern due to its toxicity and ubiquitous presence in the environment. Here we review current methods for measuring the forms of Hg in the atmosphere and models used to interpret these data. There are three operationally defined forms of atmospheric Hg: gaseous elemental mercury (GEM), gaseous oxidized mercury (GOM), and particulate bound mercury (PBM). There is relative confidence in GEM measurements (collection on a gold surface), but GOM (collection on potassium chloride (KCl)-coated denuder) and PBM (collected using various methods) are less well understood. Field and laboratory investigations suggest the methods to measure GOM and PBM are impacted by analytical interferences that vary with environmental setting (e.g., ozone, relative humidity), and GOM concentrations measured by the KCl-coated denuder can be too low by a factor of 1.6 to 12 depending on the chemical composition of GOM. The composition of GOM (e.g., HgBr2, HgCl2, HgBrOH) varies across space and time. This has important implications for refining existing measurement methods and developing new ones, model/measurement comparisons, model development, and assessing trends. Unclear features of previously published data may now be re-examined and possibly explained, which is demonstrated through a case study. Priorities for future research include identification of GOM compounds in ambient air and development of information on their chemical and physical properties and GOM and PBM calibration systems. With this information, identification of redox mechanisms and associated rate coefficients may be developed.