Rowe Bertrand R, Canosa André, Meslem Amina, Rowe Frantz
Rowe Consulting, 22 chemin des moines, 22750 Saint Jacut de la Mer, France.
CNRS, IPR (Institut de Physique de Rennes)-UMR 6251, Université de Rennes, 35000 Rennes, France.
Build Environ. 2022 Jul 1;219:109132. doi: 10.1016/j.buildenv.2022.109132. Epub 2022 May 12.
New COVID-19 variants, either of higher viral load such as delta or higher contagiousness like omicron, can lead to higher airborne transmission than historical strains. This paper highlights their implications for health policies, based on a clear analytical understanding and modeling of the airborne contamination paths, of the dose following exposure, and the importance of the counting unit for pathogens, itself linked to the dose-response law. Using the counting unit of Wells, i.e. the quantum of contagium, we develop the conservation equation of quanta which allows deriving the value of the quantum concentration at steady state for a well-mixed room. The link with the monitoring concentration of carbon dioxide is made and used for a risk analysis of a variety of situations for which we collected CO time-series observations. The main conclusions of these observations are that 1) the present norms of ventilation, are both insufficient and not respected, especially in a variety of public premises, leading to high risk of contamination and that 2) air can often be considered well-mixed. Finally, we insist that public health policy in the field of airborne transmission should be based on a multi parameter analysis such as the time of exposure, the quantum production rate, mask wearing and the infector proportion in the population in order to evaluate the risk, considering the whole complexity of dose evaluation. Recognizing airborne transmission requires thinking in terms of time of exposure rather than in terms of proximal distance.
新的新冠病毒变种，如病毒载量更高的德尔塔毒株或传染性更强的奥密克戎毒株，相比历史毒株可导致更高的空气传播风险。本文基于对空气传播污染路径、暴露后剂量以及病原体计数单位重要性（其本身与剂量反应定律相关）的清晰分析理解和建模，强调了它们对卫生政策的影响。使用威尔斯计数单位，即传染量子，我们推导出量子守恒方程，该方程可用于计算在充分混合的房间中稳态时的量子浓度值。我们建立了与二氧化碳监测浓度的联系，并将其用于对各种情况的风险分析，为此我们收集了二氧化碳时间序列观测数据。这些观测的主要结论是：1）当前的通风标准既不充分且未得到遵守，尤其是在各类公共场所，这导致了高污染风险；2）空气通常可被视为充分混合。最后，我们坚持认为，空气传播领域的公共卫生政策应基于多参数分析，如暴露时间、量子产生率、口罩佩戴情况以及人群中的感染者比例，以便在考虑剂量评估的整体复杂性的情况下评估风险。认识到空气传播需要从暴露时间而非近距离接触的角度来思考。
