Generation and characterization of four dilutions of diesel engine exhaust for a suhchronic inhalation study
Generation and characterization of four dilutions of diesel engine exhaust for a suhchronic inhalation study
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DOI：
10.1021/es035024v
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发表时间：
2004-05-01
影响因子：
11.4
通讯作者：
Grosjean, E
中科院分区：
文献类型：
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作者：
McDonald, JD;Barr, EB;Grosjean, E
啮齿动物吸入毒理学研究的暴露大气由2000康明斯ISB 5.9 L柴油发动机的排气产生，该发动机与测功机连接，并在略微修改的重型联邦试验程序循环下运行。暴露于一种清洁空气对照和四种柴油机废气水平，保持在四种不同的稀释率（300：1，100：1，30：1，10：1），产生的颗粒物质量浓度为30，100，300和1000 mug/ m（3）。对四种稀释度下的暴露进行了颗粒质量、粒度分布（在其他地方报告）、气体、半挥发性和颗粒相无机和有机化合物的详细化学形态表征。目标分析物包括金属、无机离子和气体、有机碳和元素碳、烷烃、烯烃、芳香酸和脂肪酸、芳烃、多环芳烃（PAH）、含氧PAH、含氮PAH、类异戊二烯、羰基化合物、甲氧基苯酚、糖衍生物和甾醇。暴露大气中的大部分物质是气态氮氧化物和一氧化碳，少量的挥发性有机物和由碳（约占PM的90%）和离子（约占PM的10%）组成的颗粒物质（PM）。测得的颗粒有机物种约占总有机颗粒质量的10%，主要是烷烃和脂肪酸。暴露大气中的几种组分的浓度随稀释度而变化，但由于啮齿动物和洗涤稀释空气的背景、动物源性排放物与柴油机排气组分的相互作用以及发动机输出的日常变化，因此未精确地随稀释率而变化。啮齿动物衍生的氨与废气反应，形成二次无机颗粒（在不同的速度取决于稀释），啮齿动物呼吸占挥发性有机物（特别是羰基和酸）在同一范围内的柴油机废气在最低的废气暴露浓度。发动机输出的日常变化部分涉及几种组分的差异，包括一些颗粒结合的有机物。虽然这些观察结果可能发生在几乎所有含有复杂材料混合物的吸入暴露大气中，但这里进行的物种形成首次说明了其中许多。
Exposure atmospheres for a rodent inhalation toxicology study were generated from the exhaust of a 2000 Cummins ISB 5.9L diesel engine coupled to a dynamometer and operated on a slightly modified heavy-duty Federal Test Procedure cycle. Exposures were conducted to one clean air control and four diesel exhaust levels maintained at four different dilution rates (300:1, 100:1, 30:1, 10:1) that yielded particulate mass concentrations of 30, 100, 300, and 1000 mug/ m(3). Exposures at the four dilutions were characterized for particle mass, particle size distribution (reported elsewhere), detailed chemical speciation of gaseous, semivolatile, and particle-phase inorganic and organic compounds. Target analytes included metals, inorganic ions and gases, organic and elemental carbon, alkanes, alkenes, aromatic and aliphatic acids, aromatic hydrocarbons, polycyclic aromatic hydrocarbons (PAH), oxygenated PAH, nitrogenated PAH, isoprenoids, carbonyls, methoxyphenols, sugar derivatives, and sterols. The majority of the mass of material in the exposure atmospheres was gaseous nitrogen oxides and carbon monoxide, with lesser amounts of volatile organics and particle mass (PM) composed of carbon (similar to90% of PM) and ions (similar to10% of PM). Measured particle organic species accounted for about 10% of total organic particle mass and were mostly alkanes and aliphatic acids. Several of the components in the exposure atmosphere scaled in concentration with dilution but did not scale precisely with the dilution rate because of background from the rodents and scrubbed dilution air, interaction of animal derived emissions with diesel exhaust components, and day-to-day variability in the output of the engine. Rodent-derived ammonia reacted with exhaust to form secondary inorganic particles (at different rates dependent on dilution), and rodent respiration accounted for volatile organics (especially carbonyls and acids) in the same range as the diesel exhaust at the lowest exhaust exposure concentrations. Day-to-day variability in the engine output was implicated partially for differences of several components, including some of the particle bound organics. Though these observations have likely occurred in nearly all inhalation exposure atmospheres that contain complex mixtures of material, the speciations conducted here illustrate many of them for the first time.