Sauvain Jean-Jacques, Hohl Magdalena Sánchez Sandoval, Wild Pascal, Pralong Jacques André, Riediker Michael
1 Institute for Work and Health (IST) , CH-1066 Epalinges-Lausanne, Switzerland .
J Aerosol Med Pulm Drug Deliv. 2014 Dec;27(6):449-58. doi: 10.1089/jamp.2013.1101.
Health assessment and medical surveillance of workers exposed to combustion nanoparticles are challenging. The aim was to evaluate the feasibility of using exhaled breath condensate (EBC) from healthy volunteers for (1) assessing the lung deposited dose of combustion nanoparticles and (2) determining the resulting oxidative stress by measuring hydrogen peroxide (H(2)O(2)) and malondialdehyde (MDA).
Fifteen healthy nonsmoker volunteers were exposed to three different levels of sidestream cigarette smoke under controlled conditions. EBC was repeatedly collected before, during, and 1 and 2 hr after exposure. Exposure variables were measured by direct reading instruments and by active sampling. The different EBC samples were analyzed for particle number concentration (light-scattering-based method) and for selected compounds considered oxidative stress markers.
Subjects were exposed to an average airborne concentration up to 4.3×10(5) particles/cm(3) (average geometric size ∼60-80 nm). Up to 10×10(8) particles/mL could be measured in the collected EBC with a broad size distribution (50(th) percentile ∼160 nm), but these biological concentrations were not related to the exposure level of cigarette smoke particles. Although H(2)O(2) and MDA concentrations in EBC increased during exposure, only H2O2 showed a transient normalization 1 hr after exposure and increased afterward. In contrast, MDA levels stayed elevated during the 2 hr post exposure.
The use of diffusion light scattering for particle counting proved to be sufficiently sensitive to detect objects in EBC, but lacked the specificity for carbonaceous tobacco smoke particles. Our results suggest two phases of oxidation markers in EBC: first, the initial deposition of particles and gases in the lung lining liquid, and later the start of oxidative stress with associated cell membrane damage. Future studies should extend the follow-up time and should remove gases or particles from the air to allow differentiation between the different sources of H(2)O(2) and MDA.
对接触燃烧纳米颗粒的工人进行健康评估和医学监测具有挑战性。目的是评估使用健康志愿者呼出的呼出气冷凝物（EBC）用于（1）评估燃烧纳米颗粒在肺部的沉积剂量，以及（2）通过测量过氧化氢（H₂O₂）和丙二醛（MDA）来确定由此产生的氧化应激的可行性。
15名健康非吸烟志愿者在受控条件下接触三种不同水平的侧流香烟烟雾。在接触前、接触期间以及接触后1小时和2小时重复收集EBC。通过直读仪器和主动采样测量接触变量。对不同的EBC样本分析颗粒数浓度（基于光散射的方法）以及作为氧化应激标志物的选定化合物。
受试者接触的平均空气传播浓度高达4.3×10⁵颗粒/cm³（平均几何尺寸约60 - 80nm）。在收集的EBC中可测量到高达10×10⁸颗粒/mL，粒径分布较宽（第50百分位数约160nm），但这些生物浓度与香烟烟雾颗粒的接触水平无关。尽管EBC中的H₂O₂和MDA浓度在接触期间增加，但只有H₂O₂在接触后1小时显示出短暂的恢复正常，随后又升高。相比之下，MDA水平在接触后2小时内一直保持升高。
使用扩散光散射进行颗粒计数被证明对检测EBC中的物体足够敏感，但对含碳烟草烟雾颗粒缺乏特异性。我们的结果表明EBC中氧化标志物有两个阶段：首先，颗粒和气体在肺衬液中的初始沉积，随后是与相关细胞膜损伤相关的氧化应激开始。未来的研究应延长随访时间，并应去除空气中的气体或颗粒，以区分H₂O₂和MDA的不同来源。
