Atmospheric Process of Microcystins in Airborne Cyanobacterial Aerosol

微小颗粒的悬浮物被称为“气溶胶”。气溶胶通常是由水面上的波浪破裂和气泡破裂而产生的。这些气溶胶可以从源头传播很远的距离。蓝藻是一种生长在地表水中的光合藻类，可以产生被称为“蓝藻毒素”的化合物。“许多蓝藻毒素对人类是有毒的，对于那些在蓝藻繁殖期间在水体附近生活、工作或娱乐的人来说，这是一个很大的问题。这种现象被称为有害藻华（HABs）。虽然有害藻华对公共卫生的威胁已得到充分认识，但我们对蓝藻毒素如何在环境中移动，特别是通过雾化方式移动的了解仍有许多空白。本研究的目标是通过开发一个模型来预测在赤潮期间产生的蓝藻毒素的气溶胶运输，以解决这一差距。这一目标将通过三个具体的研究目标来实现：i)利用新型光化学反应器模拟大气老化来表征蓝藻气溶胶的特性，ii)利用实验室研究数据开发计算模型来预测雾化的蓝藻毒素的大气运输，以及iii)利用在佛罗里达州赤潮事件期间收集的现场样品中蓝藻毒素的测量来评估模型。该模型的成功开发将使我们能够准确预测由赤潮事件引起的公共卫生风险。这些信息将有助于公共卫生专业人员采取主动措施，减少风险。通过培养本科生和研究生研究人员，增加国家的STEM劳动力，对社会有额外的好处。在有害藻华期间暴露于雾化蓝藻毒素的可能性尚未得到很好的研究。这个多阶段研究项目的目标是通过开发一个机制模型来预测关键的蓝藻毒素微囊藻毒素的大气命运和运输，从而提高知识。该项目将有三个具体目标。在目标1，大气老化的蓝藻气溶胶的化学和吸湿特性在一个新的室外光化学室将使用最先进的分析方法表征。在目标2中，将开发有害藻类大气反应（HAAR）模型，利用化学反应动力学速率常数和从腔室数据中获得的气溶胶特征来预测雾化微囊藻毒素的大气氧化。在目标3中，将在佛罗里达州的藻华事件期间从湖泊和河口收集现场数据，以评估雾化蓝藻毒素的大气老化。实验将采用UF - APHOR双室，允许在自然阳光下对复杂蓝藻毒素和活性化学物质的大气老化进行量化。提出的HAAR模型将极大地提高我们预测环境因素对雾化微囊藻毒素的命运和运输的影响的能力。这项研究的成功完成将回答有关环境空气中雾化蓝藻毒素寿命的基本问题，这是推动气溶胶传输科学的关键信息。社会将从中受益，通过提高预测沿海和湖滨社区有害蓝藻气溶胶风险的能力。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Suspensions of very small particles are called ‘aerosols’. Aerosols are commonly produced above bodies of water by breaking waves and burst bubbles at the water surface. Such aerosols can travel great distances from the point of origin. Cyanobacteria are a type of photosynthetic algae that grow in surface waters that can produce compounds known as ‘cyanotoxins.’ Many cyanotoxins are toxic to humans, and are of great concern to those people living, working, or recreating near water bodies during cyanobacterial blooms. Such events are called harmful algal blooms (HABs). While the public health threats of HABs are well recognized, there are numerous gaps in our knowledge about how cyanotoxins move in the environment, particularly through aerosolization. The goal of this research is to address this gap through the development of a model for predicting the aerosol transport of cyanotoxin produced during HABs. This goal will be achieved through three specific research objectives to: i) characterize the properties of cyanobacterial aerosols using a novel photochemical reactor to simulate atmospheric aging, ii) develop a computational model to predict the atmospheric transport of aerosolized cyanotoxins using data from laboratory study, and iii) assess the model using measurements of cyanotoxins in field samples collected during HAB events in Florida. Successful development of the model will allow accurate projections of public health risk due to HAB events. Such information would facilitate the use of proactive measures to lessen risk by public health professionals. Additional benefits to society result from increasing the Nation’s STEM workforce through the training of undergraduate and graduate student researchers.The potential for exposure to aerosolized cyanotoxins during HABs is not well studied. The goal of this multi-phase research project is to advance knowledge through the development of a mechanistic model for predicting atmospheric fate and transport of the key cyanotoxin microcystin. The project will have three specific objectives. In Objective 1, the chemical and hygroscopic properties of atmospherically aged cyanobacterial aerosols in a novel outdoor photochemical chamber will be characterized by using state-of-the-science analytical methods. In Objective 2, the Harmful Algae Atmospheric Reaction (HAAR) model will be developed to predict the atmospheric oxidation of aerosolized microcystin using chemical reaction kinetic rate constants and aerosol characteristics obtained from chamber data. In Objective 3, field data will be collected from lakes and estuaries during HAB events in Florida to evaluate atmospheric aging of aerosolized cyanotoxins. The experiments will employ the UF‐APHOR dual chambers, which allow for the quantification of atmospheric aging of complex cyanobacterial toxins and reactive chemical species under natural sunlight. The proposed HAAR model will vastly improve our ability to predict the influence of environmental factors on the fate and transport of aerosolized microcystins. Successful completion of this research will answer fundamental questions concerning the longevity of aerosolized cyanotoxins in ambient air, key information to advance the science of aerosol transport. Society will benefit from this through improved ability to predict the risk of harmful cyanobacterial aerosols in coastal and lakeside communities.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.