The COVID-19 pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has infected more than 14 million people globally. Recently, airborne transmission has been postulated to be a major contributor to the spread of the novel coronavirus, especially in enclosed public spaces. While many studies have demonstrated positive correlations between atmospheric pollutants and SARS-CoV-2 infection, the impact of indoor air pollutants on airborne transmission has been largely overlooked. In particular, laser printers are a primary source of particle emission that increases the concentrations of particulate matter in indoor atmosphere by releasing substantial quantities of electrostatic fine particles, at rates comparable with tobacco smoking and incense burning. We hypothesized that particles emitted from laser printers present a potential risk factor for the transmission of SARS-CoV-2 in offices and other indoor environments with high user occupancy. To test this hypothesis, we reviewed recent knowledge on the characteristics of particles emitted by laser printing, including their emission rates and accumulation in indoor air, electrostatic charges, localized emission and subsequent particle diffusion in relation to the human breathing zone. We then discuss the potential impact on the transmission of SAR-CoV-2 in indoor spaces. We found that emission rates from laser printers ranged from 10⁸ to 10¹² particles min⁻¹, and these fine particles typically remain suspended for prolonged periods in indoor air. Electrostatic charges carried by these particles can reach 260–379 e per particle, thus enhancing their surface adsorption and deposition in human airways. Localized emission by laser printers and subsequent diffusion highly increase particle concentrations near the human breathing zone.

由严重急性呼吸系统综合症冠状病毒 2 (SARS-CoV-2) 引起的 COVID-19 大流行已在全球感染了超过 1400 万人。最近，空气传播被认为是新型冠状病毒传播的主要原因，尤其是在封闭的公共场所。虽然许多研究表明大气污染物与 SARS-CoV-2 感染之间存在正相关关系，但室内空气污染物对空气传播的影响在很大程度上被忽视了。特别是，激光打印机是颗粒排放的主要来源，它通过释放大量静电细颗粒来增加室内大气中颗粒物的浓度，其速率与吸烟和焚香相当。我们假设，激光打印机发出的粒子是 SARS-CoV-2 在办公室和其他用户占用率高的室内环境中传播的潜在风险因素。为了验证这一假设，我们回顾了关于激光打印所发射粒子特性的最新知识，包括它们的发射率和在室内空气中的积累、静电荷、局部发射以及随后与人体呼吸区相关的粒子扩散。然后，我们讨论了对 SAR-CoV-2 在室内空间传播的潜在影响。我们发现激光打印机的排放率从 10 我们回顾了关于激光打印发射的粒子特性的最新知识，包括它们的发射率和在室内空气中的积累、静电荷、局部发射以及随后与人体呼吸区域相关的粒子扩散。然后，我们讨论了对 SAR-CoV-2 在室内空间传播的潜在影响。我们发现激光打印机的排放率从 10 我们回顾了关于激光打印发射的粒子特性的最新知识，包括它们的发射率和在室内空气中的积累、静电荷、局部发射以及随后与人体呼吸区域相关的粒子扩散。然后，我们讨论了对 SAR-CoV-2 在室内空间传播的潜在影响。我们发现激光打印机的排放率从 10⁸到 10 ^{12 个} 颗粒 min ^-1，这些细颗粒通常在室内空气中长时间保持悬浮。这些颗粒携带的静电荷可以达到每个颗粒260-379 e，从而增强它们在人体气道中的表面吸附和沉积。激光打印机的局部发射和随后的扩散大大增加了人体呼吸区附近的颗粒浓度。