The Coronavirus pandemic has been taking over the news for a few months now, and has imposed unimaginable changes on the daily lives of the world’s entire population. Although the situation is worrying, and rather devastating in some cases, being aware of the virus's behavior and understanding ways to avoid it seems to be the best way to deal with the crisis. COVID-19 is a respiratory disease that spreads through droplets in the air. What makes it especially dangerous is its high rate of contagion, as the virus has the ability to survive outside the human body, in the air, and on surfaces such as metal, glass and plastics, if they were not properly disinfected. But how does the virus behave on each of these materials? [Latest Update: July, 2020]
It has been evident that human-to-human transmissions have an incubation time of 2 to 10 days, spreading through air droplets. These droplets are either released through coughing and sneezing or through contaminated hands and surfaces. For a more detailed explanation, a single cough can produce up to 3,000 droplets; and according to a study by virologists in the United States, the virus can survive up to three hours after being released through air droplets. As soon as they reach surfaces, such as walls, clothing, furniture, or other objects, the virus behaves differently depending on the type of surface it lands on.
As you can see in these charts, Sars-Cov-2 (the correct name for the Coronavirus that has been causing the pandemic) remains alive on plastic and stainless steel surfaces for about 72 hours. On copper surfaces, however, the virus behaves differently, dying after 4 hours. On cardboard surfaces, the virus remains alive for about 24 hours, which triggers a great concern regarding items delivered by mail or delivery services.
Another scientific study put together 22 articles about the durability of all types of coronavirus, except for data on SARS-CoV2 itself, as it is a recent mutation. The results showed that while on glass or wood surfaces, the virus will remain present for up to 4 days, while on other materials such as aluminum, it will survive for about 8 hours only. However, and most importantly, research has shown that coronaviruses can be eradicated within one minute by disinfecting surfaces with alcohol, 0.5% hydrogen peroxide, or bleach containing 0.1% sodium hypochlorite, which are in fact common household cleaning products.
It is important to reiterate that, as it is a very new disease, there are no definitive conclusions on this matter. There are researchers who point out that the possibility of contagion from a surface can be difficult, but there are still no scientific studies to prove it. CDC (Centers for Disease Control and Prevention) published on its website that "It may be possible that a person can get COVID-19 by touching a surface or object that has the virus on it and then touching their own mouth, nose, or possibly their eyes. This is not thought to be the main way the virus spreads, but we are still learning more about how this virus spreads." Therefore, prudence seems to be the safest way to go.
In situations like this, we always end up wondering how our profession can contribute in finding solutions. Healthcare architecture is already obliged to follow design standards that avoid, as much as possible, the generation and accumulation of potential pathogens on their surfaces and systems. One notion could be the incorporation of good practices from healthcare design into other typologies, or at least considered while designing. However, it is always important to remember that natural and free resources, such as the sun and the wind, can make environments much healthier in an organic and passive way. Perhaps even thinking about self-cleaning materials, which can react to viruses and bacteria by killing them automatically, can be an interesting look towards the future of materials. The possibilities are endless, but if one thing is certain, it is that in times of crisis like this one, the best ideas are born.
- Persistence of coronaviruses on inanimate surfaces and their inactivation with biocidal agents. Available here.
- Aerosol and Surface Stability of SARS-CoV-2 as Compared with SARS-CoV-1. Available here.
- Natural Ventilation for Infection Control in Health-Care Settings. Available here.
We invite you to check out ArchDaily's coverage related to COVID-19, read our tips and articles on Productivity When Working from Home and learn about technical recommendations for Healthy Design in your future projects. Also, remember to review the latest advice and information on COVID-19 from the World Health Organization (WHO) website.