Airborne particles produced by normal speech may be enough to transmit coronavirus, influenza and other respiratory viruses, according to researchers at UC Davis. Although it’s not yet known how important this is to the spread of COVID-19, it underscores the need for strict social distancing measures.

加州大学戴维斯分校（UC Davis）的研究人员发现，正常交谈传播到空气中的粒子可能足以传播冠状病毒、流感和其他呼吸道病毒。 虽然还不知道这对COVID-19的传播有多重要，但它强调了严格保证社会距离措施的必要性。

Normal speech by individuals who are asymptomatic but infected with the coronavirus may produce enough aerosolized particles to transmit the infection, according to aerosol scientists at the University of California, Davis.

加州大学戴维斯分校的气溶胶科学家说，无症状但感染冠状病毒的人的正常交谈可能会产生足够的气溶胶粒子来传播感染。

Although it’s not yet known how important this is to the spread of COVID-19, it underscores the need for strict social distancing measures — and for virologists, epidemiologists and engineers who study aerosols and droplets to work together on this and other respiratory diseases.

虽然还不知道这对COVID-19的传播有多重要，但它强调了严格保证社会距离措施的必要性—以及病毒学家、流行病学家和研究气溶胶和液滴的工程师需要共同研究这种疾病和其他呼吸道疾病。

Aerosols are particles small enough to travel through the air. Ordinary speech creates significant quantities of aerosols from respiratory particles, said William Ristenpart, professor of chemical engineering at UC Davis. Ristenpart co-wrote an editorial about the problem to be published April 3 in the journal Aerosol Science and Technology.

气溶胶是足够小到可以通过空气传播的粒子。加州大学戴维斯分校化学工程教授 William Ristenpart说，普通的交谈会喷出呼吸颗粒产生大量的气溶胶。Ristenpart与人合著撰写了一篇关于这个问题的社论，将于4月3日在《气溶胶科学和技术》（Aerosol Science and Technology）杂志上发表。

These respiratory particles are about one micron, or one micrometer, in diameter. That’s too small to see with the naked eye, but large enough to carry viruses such as influenza or SARS-CoV-2.

这些呼吸颗粒直径约为一微米。它很小，小到肉眼看不见，但又足够大，能携带病毒，如流感或SARS-COV-2。

Last year, Ristenpart, graduate student Sima Asadi and colleagues published a paper showing that the louder one speaks, the more particles are emitted and that some individuals are “superemitters” who give off up to 10 times as many particles as others. The reasons for this are not yet clear. In a follow-up study published in January in PLOS One, they investigated which speech sounds are associated with the most particles.

去年，Ristenpart、研究生SimaAsadi和他的同事发表了一篇论文，表明声音越大，粒子发出越多，有些人是“超密集者”，他们释放的粒子多达他人的10倍。原因尚不清楚。在1月在PLOS One发表的一项后续研究中，他们调查了哪些语音产生的粒子最多。

Varied expertise required

需要各种专业知识

Calculating just how easily a virus like SARS-CoV-2 spreads through droplets requires expertise from different fields. From virology, researchers need to know how many viruses are in lung fluids, how easily they form into droplets and how many viruses are needed to start an infection. Aerosol scientists can study how far droplets travel once expelled, how they are affected by air motion in a room and how fast they settle out due to gravity.

计算像SARS-CoV-2这样的病毒如何容易通过液滴传播需要来自不同领域的专业知识。从病毒学来看，研究人员需要知道肺液中有多少病毒，它们有多容易形成液滴，以及需要多少病毒才能开始感染。气溶胶科学家可以研究液滴一旦被排出时会走多远，它们如何受到室内空气运动的影响，以及它们由于重力而沉降的速度。

“The aerosol science community needs to step up and tackle the current challenge presented by COVID-19, and also help better prepare us for inevitable future pandemics,” Ristenpart and colleagues conclude.

“气溶胶科学界需要加强和应对当前COVID-19提出的挑战，并帮助我们更好地为未来不可避免的大流行病做好准备，”Ristenpart 和他的同事总结道。