Laboratory for Earth Surface Processes, College of Urban and Environmental Sciences, Peking University , Beijing 100871, P.R. China.
Environ Sci Technol. 2013 Sep 17;47(18):10583-90. doi: 10.1021/es401394g. Epub 2013 Sep 4.
Particulate matter (PM) is a major ambient air pollutant causing millions of premature deaths each year in China. The toxicity of PM is property and size dependent. In this study, ambient PM samples collected in Beijing were divided into five size fractions with nominal aerodynamic ranges of <0.40, 0.40-1.1, 1.1-3.3, 3.3-5.8, and 5.8-10 μm. Individual size fractions were characterized for a number of properties including particle size distribution, specific surface area, zeta potential, dithiothreitol (DTT)-based redox ability, and contents of water-soluble organic carbon (WSOC), polycyclic aromatic hydrocarbons (PAHs), selected metals, and endotoxin. Human adenocarcinomic alveolar epithelial cell line A549 and small mouse monocyte-macrophage cell line J774A.1 were tested for their relative viabilities and inflammatory effects (interleukine-8 for A549 and tumor necrosis factor-α for J774A.1) after exposure to PM of various sizes. It was found that PM specific area was positively correlated with WSOC, high molecular weight PAHs, DTT-based redox ability, negatively correlated with surface zeta potential and lithophile metals. Several trace metals from combustion sources were enriched in intermediate size fractions. For both endotoxin concentrations of the PM and PM induced inflammatory cytokine expressions by the two cell lines, there were general increasing trends as PM size increased with an exception of the finest fraction, which induced the highest inflammatory effects. It seems that the size dependence of cytokine expression was associated with a number of properties including endotoxin content, zeta potential, settling velocity, metal content, and DTT-based redox ability.
颗粒物（PM）是一种主要的环境空气污染物，在中国每年导致数百万人过早死亡。PM 的毒性与其性质和大小有关。在这项研究中，采集了北京的环境 PM 样本，并将其分为五个粒径范围为<0.40、0.40-1.1、1.1-3.3、3.3-5.8 和 5.8-10 μm 的粒径范围。对各个粒径范围的特性进行了表征，包括粒径分布、比表面积、zeta 电位、基于二硫苏糖醇（DTT）的氧化还原能力，以及水溶性有机碳（WSOC）、多环芳烃（PAHs）、选定金属和内毒素的含量。用人肺腺癌细胞系 A549 和小鼠标本单核-巨噬细胞系 J774A.1 测试了它们在暴露于不同粒径的 PM 后的相对活力和炎症效应（A549 用白细胞介素-8 测试，J774A.1 用肿瘤坏死因子-α测试）。结果表明，PM 的比表面积与 WSOC、高分子量 PAHs、DTT 为基础的氧化还原能力呈正相关，与表面 zeta 电位和亲石金属呈负相关。来自燃烧源的几种痕量金属在中间粒径范围内富集。对于两种细胞系的 PM 内毒素浓度和 PM 诱导的炎症细胞因子表达，除了最细的粒径范围外，随着 PM 粒径的增加，通常呈上升趋势，而最细的粒径范围则诱导出最高的炎症效应。似乎细胞因子表达的粒径依赖性与内毒素含量、zeta 电位、沉降速度、金属含量和 DTT 为基础的氧化还原能力等特性有关。
