Source: COVID-19 Transmissions Jun 02, 2020 4 years, 6 months, 3 weeks, 2 days, 26 minutes ago
COVID-19 Transmission: Considering that the weather is now warmer and lockdown orders are being lifted, individuals are questioning: Can air conditioning tranmit COVID-19, especially the AC in public places, the office, stores or restaurants?
A few past researches raised concerns especially one study, published in
Emerging Infectious Diseases, found that nine people in Wuhan, China (the first epicenter of the new coronavirus outbreak) were infected with the virus simply by sitting near an air conditioning vent in a restaurant. According to researchers, the virus was spread by one asymptomatic diner who sat at a table in front of the AC unit. Four people at the table later tested positive for COVID-19, as did five people at neighboring tables.
https://wwwnc.cdc.gov/eid/article/26/7/20-0764_article#comment
Leading microbiologists, Dr Manish Butte, PhD, an Associate Professor in the department of microbiology, immunology, and molecular genetics at the University of California, Los Angeles told media that within a public setting, like a restaurant, office, store or gym, air conditioning might be potentially risky.
It has to do with the way AC works. Air conditioning circulates air more rapidly, which removes humidity. Water vapor can hold onto heat, so with less of it in the air once the humidity is removed, a room or space cools down. Less humidity in the air promotes evaporation, which causes droplets in the air to dry up and disappear.
It is important to understand a little about droplets ie the particles (containing mostly water, but also any pathogens our bodies may be infected with, such as the newSARS-CoV-2 coronavirus) that we expel when we breathe, talk, cough and sneeze.
It is known that a single cough releases about 3,000 droplets, while a single sneeze can release about 30,000, according to a blog post that went viral written by Dr Erin Bromage, a comparative immunologist and professor of biology specializing in immunology at the University of Massachusetts Dartmouth.
https://ohsonline.com/articles/2020/05/18/a-covid-analysis-goes-viral-how-the-virus-spreads-indoors-outdoors-and-in-other-spaces.aspx
It should be noted that different actions produce different sizes of droplets, which can travel varying distances. When an AC unit is turned on, air flow from the vent pushes these droplets through the air and potentially into other people. The air flow direction is what matters.
Dr Bromage believes that indoor spaces with ventilation systems and lots of people (such as the restaurant in the Wuhan study) are concerning from a transmission standpoint.
And Dr Butte agrees that air conditioning can definitely make droplets containing infectious virus particles spread farther. Remember, while air conditioning might make a room
feel fresher on a warm day, it’s simply recycled existing air.
Also when it comes to the Wuhan restaurant study, i
t’s important to take into account that it had a small sample size and didn’t replicate conditions in a lab.
Dr Amesh A. Adalja,an infectious disease expert and senior scholar at the Johns Hopkins Center said, “I do not necessarily think that this study is representative of transmission risk. However, it is important to be mindful of air flow patterns, especially if they are strong and create a jet stream for droplets.”
The question of should we all be ditching our air conditioning systems until the threat of COVID-19 has passed is simply answered as a NO!
Home Air conditioning is far less risky than AC in a busy public place, if you’ve been practicing social distancing measures and following all other recommendations regarding hygiene. If you haven’t had a stream of people in and out of your home, the only droplets that could be spread by air conditioning are those from you and whoever you’ve been in lockdown with.
“In a home setting where everyone is highly exposed to each other, there isn’t a need to worry about air conditioning,” says Dr Butte.
But as for air conditioned offices, malls, and restaurants, know that a risk exists, but most experts are not saying that you should refrain from venturing into public places.
Importantly, as lockdown eases, spending time in any indoor space outside your home requires a certain level of risk assessment. If you do go to a restaurant or any other busy place with air conditioning, continue to practice social distancing, be vigilant about hand-washing and not touching your face, and, as always, stay home if you feel sick or have symptoms of COVID-19.
In the meanwhile many simple recommendations might also help such as airing all rooms and spaces frequently by opening windows and doors etc.
Having the whole place frequently wiped down and mopped with disinfectants and also having the air-con units cleaned frequently.
For more on
COVID-19 transmissions, keep logging to Thailand Medical News.
