Environmental Effects on Viable Virus Transport in Ventilation Airflow at High Risk Facilities

在美国，肉类加工厂已经成为新冠病毒传播的温床。肉类加工设施的供暖、通风和空调系统提供了运输导致COVID-19的SARS-CoV-2病毒的手段。此外，这些通风系统有助于病毒颗粒沉积到表面上，在那里它们可以存活并保持数天的传染性。尽管最近进行了一系列调查，但人们对COVID-19在加工厂通过气溶胶扩散和吸入传播的情况仍然知之甚少。这项研究的目标是促进我们对加工厂中携带病毒的气溶胶传播的基本理解，并利用这些知识来减轻SARS-CoV-2的传播和传播。为了实现这一目标，研究人员将使用牛冠状病毒（SARS-CoV-2的替代品）来：i)在模拟肉类加工厂条件的模型试验室内研究病毒的雾化、运输和沉积；ii)进行病毒颗粒运输的计算建模，以预测通风系统中的行为。该项目的成功完成将通过开发新知识来了解和减轻SARS-CoV-2病毒颗粒在肉类加工厂的传播和传播，从而使社会受益，从而保护国家食品供应的重要组成部分。通过学生教育、培训和公众宣传，包括招募和指导来自代表性不足群体的学生，以及培训教师、工业和医疗合作者以及其他利益攸关方，将进一步造福社会。肉类加工厂受到当前COVID-19大流行的打击尤其严重。虽然我们知道这些工厂的低温、高湿和高气流率等条件可以促进SARS-CoV-2病毒颗粒的传播，但这些环境因素对病毒在肉类加工厂传播和传染性的相对重要性仍然知之甚少。该项目的总体目标是促进我们对肉类加工厂中病毒的雾化、运输、扩散和传染性的基本理解。为了实现这一目标，研究人员将开展一项综合实验和计算建模研究计划，利用牛冠状病毒（BCoV）作为SARS-CoV-2的替代品。实验将在温度和湿度控制的BSL-2室中进行，该室配备了使用颗粒跟踪测速仪跟踪病毒气溶胶的大小和分布的设备。在实验过程中，将定期对实验室内的表面进行采样，利用细胞培养技术和定量PCR技术来定量BCoV颗粒的数量和活力。研究人员将利用ANSYS Fluent软件对测试室内的气流模式进行建模，以确定通风对BCoV气溶胶夹带和扩散的影响。最后，研究人员将在两个大型牛肉加工车间进行实地测试，以验证和应用项目发现。通过开发新的知识和工具来预测和减轻肉类加工厂中病毒的运输、扩散和传染性，成功完成这一项目有可能产生变革性影响。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。

Meat processing plants have become hotbeds for the transmission of COVID-19 in the United States. Heating, ventilation, and air conditioning systems in meat processing facilities provide a means of transporting SARS-CoV-2, the virus that causes COVID-19. In addition, these ventilation systems facilitate the deposition of virus particles onto surfaces where they can survive and remain infectious for days. Despite a recent flurry of investigations, the spread of COVID-19 via aerosol dispersion and inhalation in processing plants remains poorly understood. The goals of this research are to advance our fundamental understanding of the spread of viruses-laden aerosols in processing plants and use this knowledge to mitigate the transmission and spread of SARS-CoV-2. To achieve this goal, researchers will use bovine corona virus, a surrogate for SARS-CoV-2, to: i) investigate virus aerosolization, transport, and deposition inside a model test chamber designed to simulate conditions in the meat processing plant; and ii) perform computational modeling of virus particle transport to predict behavior in the ventilation system. Successful completion of this project will benefit society through the development of new knowledge to understand and mitigate the transmission and spread of SARS-CoV-2 virus particles in meat processing plants, thus protecting a vital part of the Nation’s food supply. Further benefits to society will be achieved through student education, training, and public outreach including the recruitment and mentoring of students from underrepresented groups, and training for teachers, industrial and medical collaborators, and other stakeholders.Meat processing plants have been especially hard hit by the current COVID-19 pandemic. Although we know that conditions in these plants including low temperature, high humidity, and high airflow rate can facilitate the spread of SARS-CoV-2 virus particles, the relative importance of these environmental factors on virus transmission and infectivity in meat processing plants remain poorly understood. The overarching goal of this project is to advance our fundamental understanding of virus aerosolization, transport, dispersion, and infectivity in meat processing plants. To achieve this goal, researchers will carry out an integrated experimental and computational modeling research program using bovine corona virus (BCoV) as a surrogate for SARS-CoV-2. Experiments will be conducted in a temperature- and humidity-controlled BSL-2 chamber equipped to track the size and distribution of virus aerosols using particle tracking velocimetry. During the experiments, the surfaces inside the test chamber will be sampled at regular time intervals to quantify the number and viability of BCoV particles using cell culture techniques and quantitative PCR. Researchers will utilize ANSYS Fluent software to model the airflow pattern in the test chamber to determine the effect of ventilation on the entrainment and spread of BCoV aerosols. Finally, researchers will conduct field tests at two large beef processing pants to validate and apply the project findings. Successful completion of this project has potential for transformative impact through the development of new knowledge and tools to predict and mitigate the transport, dispersion, and infectivity of viruses in meat processing plants.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.