Carbonaceous aerosols emitted from indoor and outdoor biomass burning are major risk factors contributing to the global burden of disease. Wood tar aerosols, namely, tar ball particles, compose a substantial fraction of carbonaceous emissions, especially from biomass smoldering. However, their health-related impacts and toxicity are still not well known. This study investigated the toxicity of the water-soluble fraction of pyrolyzed wood tar aerosols in exposed mice and lung epithelial cells. Mice exposed to water-soluble wood tar aerosols showed increased inflammatory and oxidative stress responses. Bronchial epithelial cells exposed to the same water-soluble wood tar aerosols showed increased cell death with apoptotic characteristics. Alterations in oxidative status, including changes in reactive oxygen species (ROS) levels and reductions in the expression of antioxidant genes related to the transcription factor Nrf2, were observed and were confirmed by increased levels of MDA, a lipid peroxidation adduct. Damage to mitochondria was observed as an early event responsible for the aforementioned changes. The toxicity and health effect-related mechanisms of water-soluble wood tar were investigated for the first time in the context of biomass burning. Wood tar particles may account for major responses such as cell death, oxidative stress, supression of protection mechnaisms and mitochondrial damaged cause by expsoure to biomass burning aerosols.

中文翻译：

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生物质燃烧气溶胶引起的肺毒性机制。

室内和室外生物质燃烧排放的碳质气溶胶是造成全球疾病负担的主要风险因素。木焦油气溶胶，即焦油球颗粒，构成碳质排放物的很大一部分，尤其是来自生物质阴燃的碳质排放物。然而，它们对健康的影响和毒性仍不清楚。本研究研究了热解木焦油气溶胶的水溶性部分对暴露的小鼠和肺上皮细胞的毒性。暴露于水溶性木焦油气溶胶的小鼠表现出炎症和氧化应激反应增加。暴露于相同的水溶性木焦油气溶胶的支气管上皮细胞显示细胞死亡增加并具有凋亡特征。观察到氧化状态的变化，包括活性氧 (ROS) 水平的变化和与转录因子 Nrf2 相关的抗氧化基因表达的减少，并通过 MDA（一种脂质过氧化加合物）水平的增加得到证实。线粒体损伤被认为是导致上述变化的早期事件。首次在生物质燃烧的背景下研究了水溶性木焦油的毒性和健康影响相关机制。木焦油颗粒可能是导致细胞死亡、氧化应激、保护机制抑制以及暴露于生物质燃烧气溶胶导致的线粒体损伤等主要反应的原因。