Bisig Christoph, Roth Michèle, Müller Loretta, Comte Pierre, Heeb Norbert, Mayer Andreas, Czerwinski Jan, Petri-Fink Alke, Rothen-Rutishauser Barbara
Adolphe Merkle Institute (AMI), University of Fribourg, Chemin des Verdiers 4, 1700 Fribourg, Switzerland.
University Children's Hospital Basel (UKBB), Spitalstrasse 33, 4031 Basel, Switzerland.
Environ Res. 2016 Nov;151:789-796. doi: 10.1016/j.envres.2016.09.010. Epub 2016 Sep 23.
Ethanol can be produced from biomass and as such is renewable, unlike petroleum-based fuel. Almost all gasoline cars can drive with fuel containing 10% ethanol (E10), flex-fuel cars can even use 85% ethanol (E85). Brazil and the USA already include 10-27% ethanol in their standard fuel by law. Most health effect studies on car emissions are however performed with diesel exhausts, and only few data exists for other fuels. In this work we investigated possible toxic effects of exhaust aerosols from ethanol-gasoline blends using a multi-cellular model of the human lung. A flex-fuel passenger car was driven on a chassis dynamometer and fueled with E10, E85, or pure gasoline (E0). Exhausts obtained from a steady state cycle were directly applied for 6h at a dilution of 1:10 onto a multi-cellular human lung model mimicking the bronchial compartment composed of human bronchial cells (16HBE14o-), supplemented with human monocyte-derived dendritic cells and monocyte-derived macrophages, cultured at the air-liquid interface. Biological endpoints were assessed after 6h post incubation and included cytotoxicity, pro-inflammation, oxidative stress, and DNA damage. Filtered air was applied to control cells in parallel to the different exhausts; for comparison an exposure to diesel exhaust was also included in the study. No differences were measured for the volatile compounds, i.e. CO, NO, and T.HC for the different ethanol supplemented exhausts. Average particle number were 6×10 #/cm (E0), 1×10 #/cm (E10), 3×10 #/cm (E85), and 2.8×10 #/cm (diesel). In ethanol-gasoline exposure conditions no cytotoxicity and no morphological changes were observed in the lung cell cultures, in addition no oxidative stress - as analyzed with the glutathione assay - was measured. Gene expression analysis also shows no induction in any of the tested genes, including mRNA levels of genes related to oxidative stress and pro-inflammation, as well as indoleamine 2,3-dioxygenase 1 (IDO-1), transcription factor NFE2-related factor 2 (NFE2L2), and NAD(P)H dehydrogenase [quinone] 1 (NQO1). Finally, no DNA damage was observed with the OxyDNA assay. On the other hand, cell death, oxidative stress, as well as an increase in pro-inflammatory cytokines was observed for cells exposed to diesel exhaust, confirming the results of other studies and the applicability of our exposure system. In conclusion, the tested exhausts from a flex-fuel gasoline vehicle using different ethanol-gasoline blends did not induce adverse cell responses in this acute exposure. So far ethanol-gasoline blends can promptly be used, though further studies, e.g. chronic and in vivo studies, are needed.
乙醇可由生物质生产，因此是可再生的，这与石油基燃料不同。几乎所有汽油车都可以使用含10%乙醇的燃料（E10）行驶，灵活燃料汽车甚至可以使用85%乙醇（E85）。巴西和美国已依法在其标准燃料中加入10%-27%的乙醇。然而，大多数关于汽车排放对健康影响的研究是针对柴油废气进行的，针对其他燃料的数据很少。在这项工作中，我们使用人肺多细胞模型研究了乙醇-汽油混合物排放气溶胶可能产生的毒性作用。一辆灵活燃料乘用车在底盘测功机上行驶，分别使用E10、E85或纯汽油（E0）作为燃料。从稳态循环中获得的废气以1:10的稀释度直接作用6小时，作用于一个模拟由人支气管细胞（16HBE14o-）组成的支气管腔室的人肺多细胞模型，该模型补充了人单核细胞衍生的树突状细胞和单核细胞衍生的巨噬细胞，在气液界面培养。孵育6小时后评估生物学终点，包括细胞毒性、促炎反应、氧化应激和DNA损伤。将过滤后的空气平行应用于不同废气处理组的对照细胞；为了进行比较，该研究还包括了柴油废气暴露组。对于不同乙醇添加量的废气，其挥发性化合物，即一氧化碳、一氧化氮和总碳氢化合物，未检测到差异。平均颗粒数分别为6×10⁶/cm³（E0）、1×10⁶/cm³（E10）、3×10⁶/cm³（E85）和2.8×10⁶/cm³（柴油）。在乙醇-汽油暴露条件下，肺细胞培养物中未观察到细胞毒性和形态变化，此外，用谷胱甘肽测定法分析未检测到氧化应激。基因表达分析也显示，在任何测试基因中均未出现诱导现象，包括与氧化应激和促炎反应相关基因的mRNA水平，以及吲哚胺2,3-双加氧酶1（IDO-1）、转录因子NFE2相关因子2（NFE2L2）和NAD（P）H脱氢酶[醌]1（NQO1）。最后，用OxyDNA测定法未观察到DNA损伤。另一方面，暴露于柴油废气的细胞出现了细胞死亡、氧化应激以及促炎细胞因子增加的现象，这证实了其他研究的结果以及我们暴露系统的适用性。总之，在这种急性暴露中，使用不同乙醇-汽油混合物的灵活燃料汽油车的测试废气未诱导不良细胞反应。到目前为止，乙醇-汽油混合物可以立即使用，不过还需要进一步的研究，例如慢性和体内研究。
