Huang Junjun, Zhang Zhisheng, Tao Jun, Zhang Leiming, Nie Fuli, Fei Leilei
Institute for Environmental and Climate Research, Jinan University, Guangzhou, China.
South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou, China; Guangdong Provincial Observation and Research Station for Climate Environment and Air Quality Change in the Pearl River Estuary, Guangzhou, China.
Environ Res. 2022 Jul;210:112960. doi: 10.1016/j.envres.2022.112960. Epub 2022 Feb 18.
Ambient fine particulate matter (PM) levels in South China have been decreasing in the past decade, but the decreasing rates differed between its major chemical components, e.g., with much small rates for carbonaceous aerosols than for secondary inorganic aerosols. To investigate the sources of carbonaceous aerosols in this region, a comprehensive campaign was carried out in urban Guangzhou in the winter of 2019-2020 using a combination of various instruments. Data generated from this campaign include hourly total carbon (TC), black carbon (BC), criteria air pollutants and meteorological parameters, 4-hourly particle-bound elements, and chemically-resolved daily PM. Similar diurnal patterns were observed for TC, CO and NO, suggesting TC was very likely related to vehicle exhaust emission. Secondary organic carbon (SOC) estimated using the Minimum R squared (MRS) method accounted for 35 ± 17% of OC, indicating strong atmospheric oxidation capacity. Four major source factors for carbonaceous aerosols were identified by positive matrix factorization (PMF) model, including coal combustion, traffic emissions, soil dust and ship emissions, which accounted for 37 ± 23%, 39 ± 23%, 14 ± 10% and 10 ± 13%, respectively, of TC mass concentration, 38 ± 24%, 38 ± 23%, 14 ± 10% and 10 ± 12%, respectively, of OC mass concentration, and 29 ± 21%, 43 ± 22%, 14 ± 11% and 14 ± 15%, respectively, of EC mass concentration. Among these sources, traffic emission was the most important one, suggesting the necessity for promoting clean energy vehicles and relieving urban traffic congestion.
在过去十年中，中国南方的环境细颗粒物（PM）水平一直在下降，但其主要化学成分的下降速率有所不同，例如，碳质气溶胶的下降速率远低于二次无机气溶胶。为了调查该地区碳质气溶胶的来源，2019年至2020年冬季在广州城区开展了一项综合监测活动，使用了多种仪器。该活动产生的数据包括每小时的总碳（TC）、黑碳（BC）、标准空气污染物和气象参数、每4小时的颗粒结合元素，以及化学解析的每日PM。观察到TC、CO和NO具有相似的日变化模式，这表明TC很可能与机动车尾气排放有关。使用最小R平方（MRS）方法估算的二次有机碳（SOC）占有机碳（OC）的35±17%，表明大气氧化能力较强。通过正定矩阵因子分解（PMF）模型确定了碳质气溶胶的四个主要来源因素，包括煤炭燃烧、交通排放、土壤扬尘和船舶排放，它们分别占TC质量浓度的37±23%、39±23%、14±10%和10±13%，占OC质量浓度的38±24%、38±23%、14±10%和10±12%，占元素碳（EC）质量浓度的29±21%、43±22%、14±11%和14±15%。在这些来源中，交通排放是最重要的一个，这表明推广清洁能源车辆和缓解城市交通拥堵的必要性。
