Abstract

As unavoidable by-products of the combustion of organic matter, the sources of carcinogenic polycyclic aromatic hydrocarbons (PAHs) are an area of great research interest in environmental monitoring, environmental forensics, and organic geochemistry. Molecular diagnostic ratios, receptor models, and stable isotope analysis are the most widely used methods to identify the sources of PAHs. However, some studies have demonstrated that these conventional methods have several disadvantages including overlapping end-members (or “non-uniqueness”), unexpected “blending,” secondary reaction and degradation, which lead to ambiguous PAH source results. At the end of the last century, compound-specific radiocarbon analysis (CSRA) focusing on the molecular level radiocarbon signatures was introduced for PAH source identification, because of its effectiveness in avoiding uncertainties of the conventional methods. CSRA has an excellent ability to distinguish the fractional contributions of fossil fuels and biomass burning. Here, by reviewing the merits and limitations of conventional methods, we point out that their unquestioning application needs to be criticized in PAH source identification, and further highlight the particular advantages of CSRA. Specifically, we summarize the application and prospects of CSRA in PAH source identification. We conclude that CSRA provides a powerful tool to accurately quantify the sources of aromatic pollutants, to reveal their sedimentary radiocarbon records, and to elucidate regional energy structure and fuel consumption. In doing so, we provide a critical resource to expand the application of CSRA in environmental science. To the best of our knowledge, this is the first comprehensive review of the application of CSRA for PAH source identification.

摘要

作为有机物燃烧过程中不可避免的副产品，致癌多环芳烃（PAHs）的来源是环境监测、环境法医学和有机地球化学等领域的重要研究领域。分子诊断比率、受体模型和稳定同位素分析是识别 PAHs 来源最广泛使用的方法。然而，一些研究表明，这些传统方法有几个缺点，包括重叠的末端成员（或“非唯一性”）、意外的“混合”、二次反应和降解，从而导致 PAH 来源结果模棱两可。上世纪末，针对多环芳烃源识别引入了以分子水平放射性碳特征为重点的化合物特异性放射性碳分析（CSRA），因为它有效地避免了传统方法的不确定性。CSRA 在区分化石燃料和生物质燃烧的部分贡献方面具有出色的能力。在这里，通过回顾传统方法的优点和局限性，我们指出它们在 PAH 源识别中的应用需要受到批评，并进一步突出 CSRA 的特殊优势。具体来说，我们总结了CSRA在PAH源识别中的应用和前景。我们得出结论，CSRA 提供了一个强大的工具来准确量化芳香污染物的来源，揭示其沉积放射性碳记录，并阐明区域能源结构和燃料消耗。在此过程中，我们为扩大 CSRA 在环境科学中的应用提供了关键资源。