Detection of airborne endotoxins and toxins from cyanobacterial harmful algal blooms and the effect of atmospheric oxidants on their longevity and potency

藻类和蓝细菌自然栖息在湖泊和其他水生环境中。其中一些物种可能生长失控，形成密集的细胞聚集或有害藻华。有害生物是由营养物质的过量输入和温度升高引起的，它们在美国和全球的水体中越来越常见。一些蓝藻产生的毒素（“蓝藻毒素”），可以伤害人和动物，由于对饮用水供应和娱乐活动的影响，产生相关的经济成本。人类通过皮肤接触、饮用水和食用受污染的贝类接触这些毒素。不太清楚的是可能吸入空气中的蓝藻毒素，这可能是由于风吹过水面，导致气泡破裂并将颗粒扩散到空气中。这项研究的目的是了解赤潮期间蓝藻毒素的产生与其在空气中的存在和寿命之间的联系。这一目标将通过监测纽约长岛东部小湖中的蓝藻毒素来实现，这些小湖在夏季几个月内已知有有害生物。与此同时，空气样本将收集到过滤器上，并检查是否存在蓝藻毒素。该研究将比较多个HAB事件的现场结果，以评估关系。这项研究的成功完成将有助于缩小这一重要的知识差距，并有助于评估对人类和生态系统健康的潜在影响。这些结果将与地方和州政府机构分享，为公民保持健康提供信息。传播可用于制定水资源管理公共政策的数据，还能给社会带来其他惠益。水生生态系统中有害藻华的发生频率、严重程度和地理范围的增加，导致在经历经常性水华的地区接触蓝藻毒素的可能性增加。由铜绿微囊藻引起的赤潮是富营养化和变暖协同影响的一个明显例子。过量的营养素促进生物量的增加和微囊藻毒素的产生，这一过程在较高的温度下得到加强。在水华期间，通过风吹过水面和气泡破裂过程产生的喷雾气溶胶可以包含存在于可吸入粒径级PM-10和PM-2.5中的完整细胞、微囊藻毒素和细胞碎片。该项目的依据是，喷雾气溶胶可以促进急性呼吸窘迫远离源水华。本项目的总体目标是阐明水生系统中的蓝藻毒素生产和蓝藻毒素的空气传播之间的联系。这将通过使用大容量空气采样器/撞击系统实地收集气溶胶微粒来实现，该系统可实时时空收集气溶胶微囊藻毒素和内毒素。考虑到光化学反应性和气象条件的变化，将对空气传播的毒素的寿命和效力进行审查。模拟大气氧化过程的实验室实验将评估空气传播的毒素相对于其在大气中的停留时间的化学稳定性。该跨学科研究团队结合了有害藻华生态学、微生物学、环境有机化学、环境工程和大气气溶胶科学方面的必要专业知识，以实现项目目标。 这项研究的成功完成将提供关键的公共卫生信息，以便在与HAB管理社区和其他相关利益相关者相关的时间尺度上对潜在事件做出积极反应。该奖项反映了NSF的法定使命，并被认为值得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来支持。

Algae and cyanobacteria naturally inhabit lakes and other aquatic environments. Some of these species can grow out of control forming dense cell concentrations or harmful algal blooms (HABs). HABs are caused by excess inputs of nutrients and warmer temperatures, and they are increasingly common in waterbodies throughout the U.S. and globally. Some cyanobacteria produce toxins (‘cyanotoxins’) that can harm people and animals, with associated economic costs due to impacts on drinking water supplies and recreational activities. Humans are exposed to these toxins through skin contact, drinking water, and eating contaminated shellfish. Less well understood is the potential inhalation of airborne cyanotoxins, which likely results from wind blowing over water surfaces that cause bubbles to burst and spread particles into the air. The goal of this research is to understand the link between cyanotoxin production during HABs to their presence and lifetime in the air. This goal will be achieved by monitoring cyanotoxins in small lakes in eastern Long Island, New York, which are known to have HABs during summer months. At the same time, air samples will be collected onto filters and examined for the presence of cyanotoxins. The research will compare these field results over multiple HAB events to assess relationships. Successful completion of this research will help close this important knowledge gap and help assess the potential impacts on human and ecosystem health. These results will be shared with local and state governmental agencies to provide information for citizens to stay healthy. Additional benefits to society result from dissemination of data that can be used to develop public policy for the management of water resources. The increase in frequency, severity, and geographical extent of HABs in aquatic ecosystems has resulted in an increased likelihood of cyanotoxin exposure in areas that experience recurrent blooms. HABs caused by Microcystis aeruginosa represent a clear example of the synergistic impact of eutrophication and warming. Excess nutrients promote increases in biomass and enhanced production of microcystins, a process that is enhanced at warmer temperatures. During a bloom, spray aerosol produced via wind blowing over the water and bubble bursting processes can incorporate intact cells, microcystins, and cell fragments that exist in respirable size fractions PM-10 and PM-2.5. This project is based on evidence that spray aerosol can promote acute respiratory distress great distances from source blooms. The overall goal of this project is to elucidate connections between cyanotoxin production in aquatic systems and airborne transport of cyanotoxins. This will be achieved through field collection of aerosolized particles using a high-volume air sampler/impaction system that allows real-time spatiotemporal collection of aerosol microcystins and endotoxins. The longevity and potency of airborne toxins will be examined considering changes in photochemical reactivity and meteorological conditions. Laboratory experiments that mimic atmospheric oxidation processes will assess the chemical stability of the airborne toxins relative to their residence time in the atmosphere. The interdisciplinary research team combines necessary expertise in HAB ecology, microbiology, environmental organic chemistry, environmental engineering, and atmospheric aerosol science to achieve the project objectives. Successful completion of this research will provide critical public health information for proactive responses to potential events at time scales relevant to the HAB management community and other relevant stakeholders.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.