Third-hand smoke (THS) is a recently discovered environmental health hazard that results from accumulation and aging of second-hand smoke (SHS) toxins on surfaces of environments where smoking has occurred. Our objective was to determine whether there is a dose-dependent effect of THS exposure on biological markers of harm (BMH) using an in vivo exposure system that mimics exposure of humans to THS. THS exposure generated from as low as the 10 cigarettes-smoking regimen, resulted in increased circulating inflammatory cytokines, tumor necrosis factor alpha, interleukin 1 alpha, and granulocyte macrophage colony-stimulating factor. We also found that there was an increase in adrenocorticotropic hormone and superoxide dismutase and a decrease in ATP levels in liver tissue. Many of the altered BMH that are related to oxidative stress and decrease in ATP levels, suggest mitochondrial dysfunction. THS exposure generated from the 20 and 40 cigarettes-smoking regimen resulted in further damage. Our studies are important because virtually nothing is known about the physiological damage caused by different levels of THS exposure. These studies can also serve to educate the public on the dangers of THS and the BMH we identified can potentially be used in the clinic, once verified in exposed humans.

二手烟（THS）是最近发现的对环境健康的危害，其原因是二手烟（SHS）毒素在发生吸烟的环境表面上的积累和老化。我们的目标是使用体内方法确定THS暴露对伤害生物标志物（BMH）是否存在剂量依赖性效应模仿人类暴露于THS的暴露系统。低至10支抽烟方案产生的THS暴露导致循环炎症细胞因子，肿瘤坏死因子α，白介素1α和粒细胞巨噬细胞集落刺激因子增加。我们还发现，促肾上腺皮质激素和超氧化物歧化酶增加，肝脏组织中的ATP水平降低。许多与氧化应激和ATP水平降低有关的BMH改变，提示线粒体功能障碍。20和40支吸烟方法产生的THS暴露导致进一步的损害。我们的研究很重要，因为对于不同水平的THS暴露所造成的生理损害几乎一无所知。