Ongoing uncertainty over the relative importance of aerosol transmission of COVID-19 is in part rooted in the history of medical science and our understanding of how epidemic diseases can spread through human populations. Ancient Greek medical theory held that such illnesses are transmitted by airborne pathogenic emanations containing particulate matter (“miasmata”). Notable Roman and medieval scholars such as Varro, Ibn al-Khatib and Fracastoro developed these ideas, combining them with early germ theory and the concept of contagion. A widely held but vaguely defined belief in toxic miasmatic mists as a dominant causative agent in disease propagation was overtaken by the science of 19^th century microbiology and epidemiology, especially in the study of cholera, which was proven to be mainly transmitted by contaminated water. Airborne disease transmission came to be viewed as burdened by a dubious historical reputation and difficult to demonstrate convincingly. A breakthrough came with the classic mid-20^th century work of Wells, Riley and Mills who proved how expiratory aerosols (their “droplet nuclei”) could transport still-infectious tuberculosis bacteria through ventilation systems. The topic of aerosol transmission of pathogenic respiratory diseases assumed a new dimension with the mid-late 20^th century “Great Acceleration” of an increasingly hypermobile human population repeatedly infected by different strains of zoonotic viruses, and has taken centre stage this century in response to outbreaks of new respiratory infections that include coronaviruses. From a geoscience perspective, the consequences of pandemic-status diseases such as COVID-19, produced by viral pathogens utilising aerosols to infect a human population currently approaching 8 billion, are far-reaching and unprecedented. The obvious and sudden impacts on for example waste plastic production, water and air quality and atmospheric chemistry are accelerating human awareness of current environmental challenges. As such, the “anthropause” lockdown enforced by COVID-19 may come to be seen as a harbinger of change great enough to be preserved in the Anthropocene stratal record.

关于 COVID-19 气溶胶传播的相对重要性的持续不确定性部分源于医学科学的历史以及我们对流行病如何在人群中传播的理解。古希腊医学理论认为，此类疾病是通过空气中含有颗粒物（“瘴气”）的致病性散发物传播的。瓦罗、伊本·哈提卜和弗拉卡斯托罗等著名罗马和中世纪学者将这些想法与早期细菌理论和传染病概念相结合。人们广泛持有但定义模糊的信念，认为有毒瘴气是疾病传播的主要病原体，这一信念被¹⁹世纪微生物学和流行病学所取代，特别是在霍乱的研究中，霍乱被证明主要通过受污染的水传播。空气传播疾病的传播被认为背负着可疑的历史声誉，并且难以令人信服地证明。 Wells、Riley 和 Mills 在²⁰世纪中叶的经典工作取得了突破，他们证明了呼出气溶胶（它们的“飞沫核”）如何能够通过通风系统输送仍然具有传染性的结核病细菌。随着²⁰世纪中后期，人口流动性日益增加，反复感染不同毒株的人畜共患病毒，致病性呼吸道疾病的气溶胶传播这一话题呈现出一个新的维度，并在本世纪占据了中心舞台。包括冠状病毒在内的新呼吸道感染的爆发。 从地球科学的角度来看，由病毒病原体利用气溶胶感染目前接近 80 亿人口的 COVID-19 等大流行疾病的后果是深远且前所未有的。对废塑料生产、水和空气质量以及大气化学等的明显和突然的影响正在加速人类对当前环境挑战的认识。因此，COVID-19 实施的“人类更年期”封锁可能会被视为足以保留在人类世地层记录中的巨大变化的预兆。