关键词: 碳质气溶胶, 碳循环, 来源, 源解析, 健康效应

Abstract: Significance　 Although there are extensive research on carbonaceous aerosols, such as organic carbon (OC) and black carbon (BC), there still remains a lack of systematic overview regarding their sources and source apportionment methods, especially summary of their health impacts. Given the critical role of carbonaceous aerosols in the global carbon cycle and the complexity of their sources and health effects, this review examines their origins, source apportionment methodologies, and health consequences to provide scientific foundations for carbonaceous aerosol emission reduction and pollution control strategies. Progress　 Carbonaceous aerosols play a critical role in the global carbon cycle, with an atmospheric carbon storage of about 730 Gt C. Meanwhile, as an important component of the inert organic carbon pool, BC is widely involved in the global carbon cycle. Due to the extremely complex sources of carbonaceous aerosols, there are various methods for their source apportionment, including source receptor models, transport models, and feature ratio methods, each with its own advantages and disadvantages. Therefore, an appropriate source analysis method should be selected according to the actual situations during the source analysis for carbonaceous aerosols. The source receptor modeling approaches involve analyzing data or meteorological parameters to identify their origins. Common methodologies include Chemical Mass Balance (CMB), Principal Component Analysis (PCA), and Positive Definite Matrix Factor (PMF) Analysis. Among them, PMF models should be prioritized for scenarios where pollutant emission characteristics remain unknown and large datasets are available. The transport model approaches commonly employ two methodologies: Potential Source Contribution Factor (PSCF) and Analysis and Concentration Weighted Trajectory (CWT) Analysis . While these methods can identify specific source regions of polluted air masses, their inherent uncertainty as conditional probability analysis techniques remains significant. To mitigate this limitation, a weighting coefficient W is usually added in practical applications, resulting in Weighted Potential Source Contribution (WPSCF) Analysis and Weighted Concentration Weighted Trajectory (WCWT) Analysis to reduce analysis uncertainty. In addition, the OC/EC ratio method is commonly used to preliminarily determine the sources of carbonaceous aerosols by analyzing the proportional relationships of certain carbon components in pollutant emissions. The health impacts of carbonaceous aerosols are primarily manifested as their adverse effects on the respiratory system, nervous system, cardiovascular system, and immune system, which can induce asthma, allergic airway inflammation, cognitive impairment, arrhythmia, atherosclerosis, and other diseases. As an irritant particulate matter, BC can enter the human body through respiration. Once deposited in the respiratory tract, BC can act as a carrier for other antigens (e. g., polycyclic aromatic hydrocarbons and heavy metals) or directly induce inflammatory damage, which in turn triggers specific immune responses. In these responses, antibodies or sensitized lymphocytes react with antigens, leading to tissue cell damage and the release of biochemically active substances. This change can cause metabolic dysfunction, followed by inflammatory reactions, resulting in persistent airway injury and inducing asthma. The primary mechanism by which BC affects the nervous system is by influencing the levels of perivascular macrophages in the central nervous system. In addition, airborne pollutants can induce inflammation and oxidative stress responses in the lungs, which subsequently triggers systemic inflammation and adversely affects cardiovascular health. And there is also a correlation between air pollution (including BC) and increased risk of lung cancer. Conclusions and Prospects　Based on this review, the following conclusions and prospects are proposed for the future research directions of carbonaceous aerosols: 1) As a crucial component of inert carbon reservoirs, BC plays a significant role in the global carbon cycle. However, limited research has led to uncertainties regarding certain carbon storage and fluxes, including BC fluxes entering oceans through groundwater runoff, atmospheric carbon release from soil via respiration, erosion, and weathering processes, as well as atmospheric carbon storage capacity. These fields represent key research priorities for future breakthroughs. Currently, studies on carbon cycle and carbon sink have entered a new developmental phase, with a focus on investigating continental and marine carbon cycles on a global scale and over an extended time frame. 2) Investigating the degradation processes, degradation rates and roles of carbonaceous materials in the global carbon cycle is of great significance. Concurrently, comprehensive surveys must be conducted across different regions (e.g., urban areas, remote mountainous regions, forests, oceans) to establish regional and even global carbonaceous material databases. 3) A comprehensive understanding of the origins of carbonaceous aerosols can provide scientific guidance for energy conservation, emission reduction, and pollution control measures. And it is essential to master various source apportionment methods, including their advantages and limitations, and choose the appropriate methodology based on practical research requirements. 4) Due to their complex structures, OC and BC can adsorb toxic and harmful substances such as heavy metals and polycyclic aromatic hydrocarbons (PAHs). Current research has not yet achieved complete separation between carbon materials and the toxic substances adsorbed on their surfaces, nor can it determine which chemical components pose greater risks to human health. Therefore, further studies are required to elucidate the independent pathogenic mechanisms of carbonaceous materials and to conduct systematic, comprehensive quantitative assessments of their impacts on human health.

Key words: carbonaceous aerosols, carbon cycle, sources, source apportionment, health effects