How to lower the risk of infection while flying

[Randy W]

from the SCMP

 

 

Coronavirus: how to lower the risk of infection while flying – and remember, the air in aircraft cabins is much fresher than in your home or office

 

 

If you are worried about catching the coronavirus on a flight, relax. Airliner cabin air is changed every two to three minutes, and an infected person has to be within a metre of you to pass it on – so pick a window seat.

 

 

https://www.scmp.com/lifestyle/health-wellness/article/3050706/coronavirus-how-lower-risk-infection-while-flying-and?utm_content=article&utm_medium=Social&utm_source=Facebook#Echobox=1581774193

 

 

 

Cabin air is changed every two to three minutes, that is 20 to 30 times every hour, according to Zhu Tao, deputy director of the flight standard department under China’s Civil Aviation Administration. At a news conference last month, he also noted that cabin ventilation systems are designed for vertical, not horizontal, air flow, which effectively reduces the risk of a virus spreading on a plane.

 

This is because human-to-human transmission of the new coronavirus is believed to occur mainly through droplets, which generally are not affected by air flowing through a space, so they fall fairly close to where they originate – usually within a metre.

That is why the World Health Organisation defines “contact” with an infected passenger on a plane as having been seated within two to three rows of that person. The infection risk for those sitting outside that zone is much lower.

 

[Allon]

There is controversy about some points there. Iff circulation is as they suggest, an aisle seat has more space between flyers, unless there is a constant line to the bathroom. A window seat is surrounded within the meter distance. I also do not accept that droplets fall within the circumference of the cougher. We have all seen tests where a light is shown against a black backdrop and person's sneeze or cough is caught on high speed film. Both of them send sputum quite a ways.

 

And when someone says the air is exchanged 3 times an hour means something if there are filters that grab viruses, and those filters had better be changed pretty often by some brave people. If they mean air comes from the outside of aircraft and exchanged it still goes through filters at the rate they say. Although I would agree the air in a plane is probably a little better than that on the street over time, but the exposure part when you are sitting butt to butt -- I don't know.

 

I want the metrics. I want to see how many viruses and other bugs are found on filters and samples from people's clothes, before and after flying. Food samples. Water samples.

[amberjack1234]

I am with you on that Allon.

[Randy W]

My understanding is that aircraft air is not recycled, but is replaced by outside air.

 

At what rate, or what is done about the temperature, I don't know.

[Randy W]

Yes though, you have to wonder about the level of expertise represented in this article.

[Allon]

Yes, the air is replaced and recycled. Here is one of the better articles I found. In some I like the term "Air quality in an airplane is better than you think." Not better than I think. Sorry.

 

 

How does cabin air flow?

Here's how cabin air is circulated, filtered, and refreshed throughout most of today's aircraft:

1. Fresh air continuously enters both engines at -65 degrees. Temperature and pressure are increased, then air is passed through a control valve and cooled by additional outside air.

2. HEPA filters remove 99.7 percent of particles; new technology could destroy 100 percent of all bacteria and viruses.

3. Filtered, recirculated cabin air and fresh air are combined.

4. The aircraft is divided into ventilation segments of three to seven rows; you share air only with passengers in your segment.

5. Outflow valve continuously releases cabin air and helps maintain constant pressurization of aircraft.

© 2013 Condé Nast Traveler

http://www.nbcnews.com/id/34708785/ns/travel-travel_tips/t/airplane-air-not-bad-you-think/#.XlPp6ShKjyQ

 

Supposedly, British Air has developed a plasma system that will kill 100% of bacteria and viruses. Probably too expensive right now but may be used in aircraft. Note: regional flights do not have such air replacement and filtration. So....

[Randy W]

But I wouldn't think there would be a whole lot of air borne viruses to be picked up at that altitude - that incoming air in flight would be mostly 'fresh', and that filtering would primarily j%

[Allon]

Randy, I worked 4 years as a surgical tech in a hospital surgery to the point of boredom. I have had the lectures we got as a required regulation, and the procedures we had to follow. Every time a doctor came to take a specimen from our autoclaves, we had to listen to him/her talk about the latest in "germs" which we just called "bugs."

 

A virus will live anaerobically, that is without oxygen, in any altitude, even a vacuum., even in an autoclave if it is resistant enough. Bacteria will "spore" and can be almost as difficult to kill. But they can be killed with right tools and procedures. We have all read about that stuff......

 

Some viruses from my understanding (and Greg, please correct as I did not finish my microbio studies) are actually composed of RNA or ribonucleic acid, smaller than DNA itself. RNA latches on to other cells and infects them. The coronavirus has spines on it that some have indicated may assist to do that "latching." (The spines supposedly give it that "corona" look under a microscope. (I am not sure that characteristic has been verified but I am very curious.)

 

By the way, how are those 401K's and IRA's doing?

[Randy W]

I consolidated all my 401Ks into a single IRA, which is doing excellently, thank you.

 

The advantage of fixed income (SS and the rental building for us) is that you can choose when to make withdrawals from the non-fixed investments based on market conditions.

[Greg.D.]

When a virus emerges from its host cell, it buds out through the membrane, taking pieces of the membrane with it, which becomes its coat. The coat can be studded with proteins ("spike" proteins) that are coded for by the virus genome (in this case the single stranded RNA) and made during virus replication.

 

In the case of this coronavirus, it codes for a spike protein that is a nice fit for binding with a protein we all have on the outside of our cells called angiotensin converting enzyme 2 ("ACE") and, once bound, can facilitate a cascade of events that allows for its transduction into the cell. The single strand, + orientation means it's ready to serve as a template for more virus proteins including those that will make copies of its RNA to reemerge from the cell, packaging itself in a new coat in the process, only now it is many copies of itself.

 

Our tissue's response to the infection of our lung cilia can plug up our alveoli (visible by X-ray) and even leave lasting damage if we survive. Some viruses like HIV have a very short life span outside host tissue (why you can't catch it from a toilet seat) whereas this Covid-19 needs a moist environment but apparently can survive longer - like in the taxi last used by an infected person and you just got in it.

 

Just want to say here that the personal protection equipment they use like the gowns, gloves and masks are considered contaminated from first use in the clinical setting and should be removed in a precise sequence and location ("degowning") when transitoining from the contaminated area (place where a sick, coughing patient is) to the next location. Remove when taking a break or eating, too! To me, the avoidable tragedy in Hebei is not the lack of 50,000 spare, equipped hospital beds (the U. S. would be in a similar bind)) but the infection of 3000 health care workers.

 

Allon would have been familiar with these safety protocols as second nature from his clinical experience and, given China being factory to the world, the well-trained caregivers shouldn't have had such an uphill struggle for protecting themselves.

[Allon]

Yes, it is remarkable how many trained and knowledgeable "workers" including doctors, got the disease, and died, when they already were trained in sterile technique for a normal flu or cold. But it's the nature of the beast. I saw technique mistakes made all the time and committed them myself. Even when I studied microbio in college, I am amazed more did not come down with some of the stuff we helped with in the research labs. Just using tubes and tools was a real hazard I shudder to think about now. Fortunately, we used some very strong (and carcinogenic) bug killers.

 

Speaking of "moist" environments, a grad student friend of mine went around with a sample kit and tested the droplets around the toilets at the university as part of a paper. He found live staph, syph, and gonorrhea in some of the puddles. He went in right after someone used the toilet. Apparently, there are other studies confirming. Those are bacteria not viruses, but it shows how vulnerable we are.

 

But the CDC is now saying they will filter any further news as they are worried about information overload. My sister said last night, "I hear it all day." So she shuts down and won't pay attention when it might be really serious. On the other hand, my wife (Chinese) has family near the drop zone. She shuts down from abject fear. It borders on PTSD, which I have and have seen many times.

[amberjack1234]

My wife has PTSD when it comes to pathogens of any kind and I mean she really goes ballistic too. Way over the top.

 

I see the infractions all the time even in hospitals and what is with wearing a face mask and leaving your nose uncovered. How ridiculous is that? Doctors wearing a mask that you can put two fingers between the side of his/her face and the mask. Wast of a mask. May as well throw it in the trash and save you some discomfort.

[Martin B]

Recently my wife has been getting super paranoid about the coronavirus coming here. She insisted that we take some "minor" steps as an insurance policy. She's also worried about everything getting bought out if the situation gets bad enough.

 

We typically keep anywhere from 8-12 weeks of "staples" (toilet paper, soap, kleenex, toothpaste etc.) on hand. We made a late night run to Costco to extend that supply to a year. We're going to go through that stuff anyways so I guess there's really no harm in having some things stockpiled. And it may save us a few trips down the road.

 

We also set aside a two-month food/water supply. Mostly things like rice, beans, nuts, peanut butter, pureed fruits/vegetables etc. with a shelf-life of 1+ year that will be consumed anyways. Also made sure that our supply of OTC medicines like Advil/Tylenol was up to at least a year, and several extra boxes of diapers and other misc baby items.

 

And several math/English workbooks for my stepdaughter in case school gets cancelled .

 

We did spend $100 on masks (including the N95 ones) and hand sanitizer - that's really the only stuff that may not be used if the coronavirus (hopefully) peters out.

 

 

My wife has PTSD when it comes to pathogens of any kind and I mean she really goes ballistic too. Way over the top.

 

I see the infractions all the time even in hospitals and what is with wearing a face mask and leaving your nose uncovered. How ridiculous is that? Doctors wearing a mask that you can put two fingers between the side of his/her face and the mask. Wast of a mask. May as well throw it in the trash and save you some discomfort.

 

My understanding is that those are okay if everyone is wearing one and do a good job of protecting other people by slowing down the viruses trajectory to some extent and absorbing water droplets if someone coughs or sneezes. At least that's my understanding. That's why the Chinese government required everyone to wear a mask going outside.

Edited February 28, 2020 by Barfus (see edit history)

[Allon]

CDC has some really helpful information here.....

 

https://www.cdc.gov/coronavirus/2019-ncov/index.html

[amberjack1234]

Some really good stuff there. Been there before. But you know it is kinda like we use to say in the fire department. "You can accumulate "50 atta- boys" and "one aw-shit will wipe them all out."