Comparison of Diesel and Biodiesel Emissions and Health Effects in Underground Mi

描述(由申请人提供)：评估和比较在地下采矿中接触柴油和生物柴油废气以及对健康的急性影响。背景：尽管矿井通风和排放受到控制，但井下矿工暴露在柴油废气中的浓度经常超过MSHA关于柴油颗粒物的160微克/立方米的标准。作为一种已知的致癌物质，柴油排放还与一系列呼吸和心血管健康影响有关，包括急性和慢性影响。最近，使用生物柴油作为柴油燃料的混合物已被推广为减少颗粒物暴露的一种手段。然而，目前还没有研究评估与混合生物柴油相比，接触柴油设备排放的废气对健康的影响，一些体外研究表明，使用生物柴油会产生更大的毒性。具体目标：1)评估与地下矿山使用柴油和生物柴油混合燃料的设备有关的吸入暴露；2)评估与接触柴油和生物柴油混合动力设备产生的废气有关的健康影响和生理改变的生物标志物；以及3)比较与接触柴油和生物柴油混合燃料的排放物有关的健康影响和改变生理的生物标志物的差异。研究设计：采用交叉实验设计，交替使用柴油和50%生物柴油/柴油混合物(B50)燃料，采矿和矿物工程专业的学生在地下矿山操作装载自卸汽车，将被监测污染物暴露和对健康的影响。将从矿井中采集呼吸性粉尘、元素碳、黑碳、二氧化氮(NO2)、二氧化硫(SO2)、一氧化碳(CO)、醛和多环芳烃(PAHs)。所有受试者在暴露前和暴露后都将收集肺活量、症状、痰、血、尿、呼出气和超声检查。诱导痰中的炎症标志物和氧化应激标志物，包括白介素6、8和10、髓过氧化物酶和基质金属蛋白酶9将被分析。将分析血液中血管损伤的介质，包括P-选择素和内皮素-1(ET-1)。尿8-羟基-2‘-脱氧鸟苷(8-OHdG)将被检测以评估DNA氧化损伤。呼出的一氧化氮(NO)和呼出的一氧化碳(CO)都将被评估，前者是呼吸道炎症的标志，后者是一氧化碳暴露的标志。血管内皮细胞功能的改变将被用于评价血流介导的臂部扩张的超声检查。暴露前和暴露后的生物标志物的配对差异将与接触柴油和B50生物柴油的情况进行比较。对于每种燃料类型，将使用回归分析来模拟排放污染物对暴露前和暴露后单个生物标志物变化的影响。与公众健康的相关性：这项研究将有助于确定在地下采矿环境中使用生物柴油混合燃料的健康后果。关于在职业和环境环境中转用生物柴油燃料对健康的影响的信息也将有助于为今后的政策决定提供信息。

DESCRIPTION (provided by applicant): To evaluate and compare exposure to diesel and biodiesel emissions and acute health effects in underground mining. Background: Despite mine ventilation and emission controls, underground miners are exposed to concentrations of diesel exhaust that frequently exceed the MSHA standard of 160 ¿g/m3 for diesel particulate matter. A known carcinogen, diesel emissions have also been linked to a broad range of respiratory and cardiovascular health effects, both acute and chronic. Recently, use of biodiesel fuel as a blend with diesel fuel has been promoted as a means of reducing particulate exposure. However, there have been no studies evaluating the health effects of exposure to emissions from equipment running on diesel fuel as compared with a biodiesel blend, and some in vitro studies suggest greater toxicity from biodiesel use. Specific aims: 1) Evaluate inhalation exposures associated with use of diesel and biodiesel blend-fueled equipment in an underground mine; 2) Evaluate health effects and biomarkers of altered physiology associated with exposure to emissions generated using diesel and biodiesel blend-powered equipment; and 3) Compare the differences in health effects and biomarkers of altered physiology associated with exposure to diesel and biodiesel blend emissions. Study design: Using a cross-over experimental design alternating use of diesel and 50% biodiesel/diesel blend (B50) fuels, mining and mineral engineering students operating a load-haul-dump vehicle in an underground mine will be monitored for exposure to contaminants and health effects. Respirable dust, elemental carbon, black carbon, nitrogen dioxide (NO2), sulfur dioxide (SO2), carbon monoxide (CO), aldehydes, and polycyclic aromatic hydrocarbons (PAHs) will be sampled from the mine. Spirometry, symptoms, sputum, blood, urine, exhaled breath and ultrasonography will be collected on all subjects pre- and post-exposure. Inflammatory markers and markers of oxidative stress, including interleukin (IL)-6, -8 and -10, myeloperoxidase (MPO), and matrix metalloproteinase-9 (MMP-9) will be analyzed in induced sputum. Blood will be analyzed for mediators of vascular damage including P-selectin and endothelin-1 (ET-1). Urinary 8- hydroxy-2'-deoxyguanosine (8-OHdG) will be assayed to assess oxidative DNA damage. Exhaled nitric oxide (NO), a marker of airway inflammation, and exhaled carbon monoxide (CO), a marker of CO exposure will both be evaluated. Ultrasound of brachial flow-mediated dilation will be used to evaluate changes in vascular endothelium function. The paired differences in pre- and post-exposure biomarkers of effect will be compared for exposures to diesel and B50 biodiesel. For each fuel type, regression analysis will be used to model the effects of emissions contaminants on pre- to post-exposure changes in individual biomarkers. Relevance to public health: This study will help determine the health consequences of use of biodiesel fuel blends in the underground mining setting. Information on the health effects of conversion to biodiesel fuels in occupational and environmental settings will also help to inform future policy decisions.