On Interpersonal Distance, Time of a Conversation and Perceived Virus Exposure

Most COVID-19 infections are caused by airborne corona viruses. A model based on empirical and theoretical studies of dispersion of particles in the air was used to estimate a person’s virus exposures during different times and distances from a virus infected person. Participants judged perceived virus exposure at different interpersonal distances in a face to face conversation with an infected person. The smallest average face to face distance from an infected person without a mask that a participant judged as sufficiently safe was 13.5 meters. A majority (75%) of the participants underestimated the effect on virus exposure following a change of interpersonal distance. By way of contrast, judgments of exposure as a function of the duration of a conversation were unbiased. The results are important for administrators and communications to the general public about social distancing and infection risks.

绝大多数新型冠状病毒肺炎（COVID-19）感染由空气传播的冠状病毒引发。本研究基于空气中颗粒物扩散的实证与理论研究构建模型，用于估算个体在与感染者不同时长、不同间距场景下的病毒暴露量。受试者在与感染者面对面交谈的场景中，对不同人际间距下的感知病毒暴露程度进行评判。受试者认为足够安全的、与未佩戴口罩感染者的最小平均面对面间距为13.5米。75%的受试者低估了人际间距变化对病毒暴露量的影响程度。相较而言，受试者对随交谈时长变化的病毒暴露程度的评判无系统性偏差。本研究结果可为公共管理者制定社交距离防控政策、向公众普及感染风险相关知识提供重要参考。