RAPID: The Role of Aerosolization from Wastewater Systems in the Fate and Transport of and Exposure to Ebola Virus

就公共健康而言，水处理和废水处理是20世纪最伟大的工程成就。废水处理系统大大降低了肠道(胃肠道)疾病的发病率，该疾病仍然是发展中国家儿童死亡的主要原因。最近爆发的埃博拉病毒病引发了人们对废水中可能接触病毒的新担忧，不仅是通过直接接触，也是通过吸入雾化飞沫。先前的工作表明，厕所、下水道系统和废水处理厂(WWTP)可以产生生物气溶胶。人们经常认为，发达国家的医疗保健优于欠发达地区，但某些技术方面实际上可能导致不太令人满意的后果。需要进行研究，以确定埃博拉病毒实际上可以在多大程度上被废水系统雾化，从厕所的使用点到下水道环境，最终在污水处理厂。关于废水系统中埃博拉病毒气雾化的可能性，存在几个关键的知识空白。以前的研究没有审查废水系统产生的丝状病毒的气雾化，甚至没有基本信息，如废水系统产生的气溶胶的大小、分布和总数。废水系统中微生物从人类排泄物到液体、气溶胶和表面的分配尚未被考虑。此外，目前尚不清楚埃博拉病毒在从废水中雾化后是否能够存活。鉴于埃博拉病毒病的高死亡率，以及围绕废水气雾化的许多悬而未决的问题，这项研究对于确保可能接触废水的工人的安全至关重要。该项目的结果将支持实用的解决方案，如安装马桶盖或提出安全工作做法和使用个人防护装备的建议。这项研究的总体目标是评估在污水系统正常运行和维护期间吸入埃博拉病毒的可能性。我们将在三个废水系统(冲水马桶、实验室规模的下水道模型和实验室规模的曝气池)中种植埃博拉病毒替代品，量化气溶胶的数量，并测量载体气溶胶的尺寸分布。使用这些信息，PI将预测病毒的命运和附近工作人员吸入的剂量。具体目标是(1)量化废水系统产生的埃博拉病毒替代品和总气溶胶的排放量和粒度分布；(2)确定埃博拉病毒替代品在水、粪便和表面之间的分配；(3)预测雾化病毒的命运和潜在的吸入剂量。该项目将产生有关废水系统(包括厕所、下水道和曝气池)产生的气雾化病毒数量和载体气溶胶大小的新数据。由于气溶胶的大小在很大程度上决定了大气中的命运，因此这一知识对于预测废水系统中埃博拉病毒的气雾化带来的风险至关重要。虽然已经在现场调查了下水道和污水处理厂中生物气溶胶的形成，但我们将首次在受控的实验室条件下检查生物气溶胶的产生。该项目还将产生关于被包裹的病毒在废水系统中的水、固体和表面之间分配的新信息。最后，该项目将首次定量估计在废水系统正常运行和维护期间雾化吸入埃博拉病毒的可能性。

1509493MarrWater treatment and wastewater treatment are the greatest engineering achievements of the 20th century in terms of public health. Wastewater systems have helped drastically reduce the incidence of enteric (gastrointestinal) disease, which remains a leading cause of childhood mortality in developing nations. The recent outbreak of Ebola virus disease has raised new concerns about the potential for exposure to the virus in wastewater, not only through direct contact but also through inhalation of aerosolized droplets. Prior work has shown that toilets, sewer systems, and wastewater treatment plants (WWTPs) can generate bioaerosols. It is often assumed that medical care in the developed world is superior to that in less developed areas, but there are certain technological aspects that may in fact lead to less desirable consequences. Research is needed in order to determine the extent to which Ebola virus could in fact be aerosolized by wastewater systems, from the point of use at a toilet to the sewer environment and ultimately in WWTPs. There are several critical knowledge gaps regarding the potential for aerosolization of Ebola virus from wastewater systems. Prior studies have not examined the aerosolization of filamentous viruses from wastewater systems, and even fundamental information, such as the size distribution and total number of aerosols generated from wastewater systems, is not available. Partitioning of microorganisms from human waste to liquid, aerosols, and surfaces in wastewater systems has not been considered. Additionally, it is not known whether Ebola virus is able to survive after being aerosolized from wastewater. Given the high mortality rate of Ebola virus disease and the many unanswered questions surrounding aerosolization from wastewater, this research is critical for ensuring the safety of workers who may come into contact with wastewater. Results from this project will support practical solutions, such as installing toilet lids or informing recommendations for safe work practices and use of personal protective equipment.The overall goal of this research is to assess the potential for inhalation exposure to Ebola virus that is aerosolized during the regular operation and maintenance of wastewater systems. We will seed Ebola virus surrogates into three wastewater systems (flush toilets, a laboratory-scale sewer model, and a laboratory-scale aeration basin), quantify the amount aerosolized, and measure the size distribution of the carrier aerosols. Using this information, the PIs will predict the fate of the virus and the dose inhaled by nearby workers. The specific objectives are to (1) quantify the emission rate and size distribution of Ebola virus surrogates and total aerosols produced by wastewater systems; (2) determine the partitioning of Ebola virus surrogates between water, stool, and surfaces; (3) predict the fate of the aerosolized viruses and potential inhaled dose. This project will produce novel data about the number of aerosolized viruses and the size of the carrier aerosols produced by wastewater systems, including toilets, sewers, and aeration basins. Because aerosol size largely dictates fate in the atmosphere, this knowledge is critical for predicting the risk posed by aerosolization of Ebola virus from wastewater systems. While bioaerosol formation in sewers and WWTPs has been surveyed in the field, we will examine generation of bioaerosols for the first time under controlled laboratory conditions. This project will also produce novel information about the partitioning of an enveloped virus between water, solids, and surfaces in wastewater systems. Finally, this project will provide the first quantitative estimate of the potential for inhalation exposure to Ebola virus that is aerosolized during the regular operation and maintenance of wastewater systems.