Characterization of Red Tide Aerosols

赤潮气溶胶的表征

• 批准号: 7131152
• 负责人: YUNG SUNG CHENG
• 金额: $ 22.36万
• 依托单位: UNIVERSITY OF NORTH CAROLINA WILMINGTON
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-09-08 至 2011-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7131152
• 关键词: aerosols; air sampling /monitoring; analytical chemistry; atmosphere /weather; biomarker; brevetoxin; disease /disorder etiology; environmental exposure; environmental health; epidemiology; field study; high performance liquid chromatography; human subject; inhibitor /antagonist; mathematical model; model design /development; respiratory disorder; respiratory toxin; water sampling /testing

The Florida red tide, produced by the dinoflagellate Karen/a brevis, occurs almost annually and has adverse economic and health effects. Exposure of people to sea spray containing aerosolized K. brevis causes irritation of the eyes, nose, and throat, as well as bronchoconstriction in some individuals. In the first 5 years of the program project, we have developed methods to characterize red tide aerosol and to assess personal exposure. We have obtained information on the brevetoxin level produced by K. brevis on the beach and particle size distribution during exposure and non-exposure periods. We have developed dose estimates of the inhaled red tide aerosol and have showed an association of airborne brevetoxins to the observed respiratory effects. We also have shown that PbTx is a component of the marine aerosol generated from a wave-powered bubble mechanism. The concentration of PbTx aerosol during the red tide episodes is usually below 100 ng/m3, which is sufficient to increase respiratory symptoms in human subjects in an occupational exposure study and studies involving asthma patients as described in the the Project by Flaming. The measured red tide aerosol particle size is in the coarse particle mode (>1 mu m in diameter) with a mass median aerodynamic diameter between 6 to 9.6 (mu m. The dose estimate based on the measured particle size showed a total deposition fraction of 82 to 89% in the human respiratory tract. The majority of inhaled red tide aerosol deposited in the upper airway (nasal, oral, pharynx and larynx region) with small but not insignificant deposition (3 to 7%) in the lower airways. The inhaled red tide aerosol has high deposition efficiency in the respiratory tract and the pattern of deposition would help to explain the observed respiratory symptoms. Our dose estimate indicates that several ng of deposited PbTx in a certain region of the human respiratory tract could be associated with observed symptoms in upper airway and/or lower airway systems. Our dose estimate shows that exposure to air concentrations as low as 3 to 5 ng/m3 may be sufficient to relate to upper airway symptoms, and higher PbTx concentrations of 30-40 ng/m3 may be required to cause lower airway symptoms for asthmatics. It also shows that brevetoxin is one of the most potent substances associated with human respiratory effects. Our colleagues at the Toxin Probes and Assays continue to separate and identify compounds from K. brevis cultures with structures related to the brevetoxin. These include the new brevetoxins (PbTx-11,12), and brevenals (antagonists of respiratory effects). As these new compounds are identified, we also need to quantify them in red tide aerosol samples obtained in the field study. In addition, our results show temporal variation of the PbTx profile during the sampling period as environmental conditions change. Therefore, it will be useful to improve the assessment of personal exposure and local deposition pattern in the upper airway to relate the observed respiratory symptoms with individual exposure. Based on this new information, we propose to continue studies to further characterize red tide aerosol and to investigate the means to predict and minimize red tide aerosol exposure. The overall objectives of our proposed study are (1) to identify red tide aerosol components that may have implications for respiratory heath effects including PbTxs, antagonists, and congeners, (2) to improve assessment of personal exposure and biomarkers for exposure, (3) to improve the understanding of marine aerosol formation and transport processes, and (4) to develop a model of the red tide aerosol in the affected area. Information gained from these studies will aid in evaluation of human risk associated with inhalation of red tide aerosols, and provide a means to predict red tide aerosol events, which may help to minimize future exposures to red tide aerosol.

佛罗里达州的红潮由双鞭毛藻Karen/a brevis产生，几乎每年都会发生， 对经济和健康造成不利影响。人们暴露在含有喷雾化短克雷伯氏菌的海雾中 眼睛、鼻子和喉咙的刺激，以及一些人的支气管收缩。在头5年里 在计划项目中，我们已经开发了方法来表征赤潮气溶胶和评估个人 曝光。我们已取得有关K.brevis在海滩上产生的短杆菌毒素水平的资料，以及 暴露和非暴露期间的颗粒大小分布。我们已经开发出了剂量估计 吸入的赤潮气溶胶显示空气中的短杆菌毒素与观察到的 对呼吸的影响。 我们还证明了PBTX是由波浪动力产生的海洋气溶胶的一种成分 气泡机制。红潮发生期间的PBTX气溶胶浓度通常在100以下。 Ng/m~3，这足以增加人类在职业接触中的呼吸道症状 研究和涉及哮喘患者的研究，如燃烧项目中所述。测量到的赤潮 气溶胶颗粒大小为粗颗粒模式(直径1微米)，空气动力学质量中位数 直径在6到9.6(微米)之间。根据测量的颗粒大小进行的剂量估计显示 在人体呼吸道中的沉积分数为82%至89%。大部分被吸入的赤潮气溶胶 沉积在上呼吸道(鼻、口、咽和喉部)，沉积小但不明显 (3%至7%)在下呼吸道。吸入赤潮气溶胶在呼吸道有很高的沉积效率 呼吸道和沉积模式将有助于解释观察到的呼吸道症状。我们的剂量 估计表明，在人类呼吸道的某个区域沉积的几ng PBTX可能是 与观察到的上呼吸道和/或下呼吸道系统的症状有关。我们的剂量估算显示 暴露于低至3至5纳克/立方米的空气浓度可能足以与上呼吸道有关 症状，可能需要较高的PBTX浓度(30-40 ng/m~3)才能引起下呼吸道症状 对哮喘患者来说。它还表明，短杆菌毒素是与人类有关的最有效的物质之一 对呼吸的影响。 我们在毒素探测和化验部门的同事继续从短杆菌中分离和鉴定化合物 具有与短杆菌毒素相关结构的培养物。这些包括新的短杆菌毒素(PBTX-11，12)，以及 百里香(呼吸作用的拮抗剂)。随着这些新化合物的鉴定，我们还需要 在实地研究中获得的赤潮气溶胶样本中对它们进行量化。此外，我们的结果表明，时间 采样期内PBTX谱随环境条件变化的变化。因此，它将 有助于改善个人暴露和上呼吸道局部沉积模式的评估，以 将观察到的呼吸道症状与个人接触联系起来。 根据这些新资料，我们建议继续研究红潮气溶胶的特征。 并研究预测和减少赤潮气溶胶暴露的方法。我们的总体目标是 建议进行的研究包括：(1)确定可能对呼吸系统健康有影响的红潮气溶胶成分 影响包括PbTx、拮抗剂和同系物，(2)改善个人暴露评估和 暴露的生物标志物，(3)提高对海洋气溶胶形成和运输的了解 (4)在受影响地区建立赤潮气溶胶模型。从以下方面获得的信息 这些研究将有助于评估与吸入赤潮气溶胶有关的人类风险，并提供 预测赤潮气溶胶事件的方法，这可能有助于将未来赤潮气溶胶的暴露降至最低。