Hello everyone, today I will be looking into the importance of Ventilation in the COVID-19 context. This is blog post serves as a continuation from the previous posts on COVID-19 and air pollution.
A recent article from Guardian discusses the German government’s formula in mitigating COVID-19, with relations to the importance of providing sufficient ventilation especially indoors (Connolly, 2020). While some people may claim this to be a basic form of mitigation, German’s Angela Merkel pointed out that this “may be one of the cheapest and most effective ways of containing the spread of the virus” (Connolly, 2020). The government is seen to raise awareness of this method entitled as Impact ventilation, or Stosslüften, which simply involves widely opening a window in the morning and evening for at least five minutes to allow the air to circulate (Connolly, 2020). As recently discovered that 90% of Covid-19 patients got the virus indoors (Connolly, 2020).
The approach above is important to lower the concentrations of indoor air that could be filled up with pollutants or contaminants including viruses in suspension in the air. Increasing ventilation by allowing the amount of outdoor air coming into indoors is important to ensure proper ventilation within indoors. This helps to reduce the concentration of airborne pollutants or contaminants which can be a medium where viruses are attached to. For instance, opening windows several times in the day and operating fans to allow outdoor air to come in and increase ventilation rate indoors. Hence we can see that poor ventilation in confined indoor spaces can be associated with increased transmission of airborne pollutants and viruses. While the role of ventilation to prevent COVID-19 is not well-studied or proved good results, preventing the dispersal of infectious diseases or the accumulation of pollutants will facilitate to minimise the risk of transmission.
As in the early stages of COVID-19, it was thought that it is primarily transported via large respiratory droplets, but a wide number of reports have shown otherwise. Increasingly, the role of aerosols in COVID-19 further implicate the outbreak as the aerosols are small droplets and droplet nuclei that remain in suspension in the air longer than large droplets (ECDC, 2020).
Another issue is that air conditioning can facilitate the spread of respiratory droplets carrying COVID-19 via the air movement. For instance, the authors of the first outbreak in China in January 2020 attribute air conditioning systems to facilitate the movement of the transmission of air droplets. “The attack rates in the outbreak were highest among those who shared a 100-minute bus ride with the index case (23 out of 67 passengers; 34%).” It was found out that passengers sitting closer to the index case did not have a statistically higher risk of COVID-19 than those sitting further away. However, all passengers sitting close to a window remained healthy. This supports the hypothesis that the airflow along the bus facilitated the spread of the virus.
In conclusion, the transmission of COVID-19 is seen to often occurs in closed indoor spaces and air-conditioning units may facilitate the spread of droplets by infected people through the airflow to longer distances within indoor spaces. Thus, more attention is needed to mitigate the virus that causes COVID-19, which can remain suspended in the air, unless there is an air or proper ventilation to remove them from remaining indoors.
Thank you everyone for reading!
For the next blog post, I will be bringing in new perspective on air pollution in China gaining rebound especially in the context of post-lockdown as China eases its restrictions.
See you soon!
References:
https://www.ecdc.europa.eu/sites/default/files/documents/Ventilation-in-the-context-of-COVID-19.pdf
https://www.theguardian.com/world/2020/sep/30/germans-embrace-fresh-air-to-ward-off-coronavirus