DO AIRLINES SPREAD SARS?

Why do so many people become ill with a variety of minor and not-so-minor maladies soon after flying on commercial airlines? And could there be a connection between this syndrome and the worldwide SARS epidemic?

I recently spoke with a good friend who had just returned from a trip to Utah. I hardly recognized his voice. At some point on his trip he had picked up a sickness that produced heavy coughing and an extremely sore throat. He was flat on his back for two days as a result. He said something very interesting: "I never get sick except after I fly."

Bells started going off in my head. I had heard similar comments from many people over the years.

I myself often come down with a cold or flu symptoms after flying on commercial airliners. I have long been aware of the research into the connection between flying and contagious diseases.

But what caused me to become very interested in this subject at this time was the worldwide concern with SARS (Severe Acute Respiratory Syndrome).

Worldwide there have been 3,288 reported cases of SARS resulting in 170 deaths. It is likely that there have been far more cases, as the disease is so new that many physicians and health-care workers have not been trained to recognize it. In addition, there have been documented cases of Chinese hospitals lying about the number of SARS cases, hiding SARS patients from inspection teams, and even filing false death certificates to cover up the number of SARS deaths.

What does this have to do with the airlines? For many years there has been concern over the quality of air in airplane cabins. The CDC (Centers for Disease Control) is just one of many health organizations that has expressed concern over diseases acquired while flying. An article in World Airline News (linked below) states, "The problem may be aggravated by the growing use of recirculated air, a fuel-saving measure that may increase the potential for disease transmission in the cabin."

You read it right. Saving fuel is more important than your health. I did a survey of four of the largest airlines in preparation for writing this article.

I was shocked at the cavalier attitude the airline representatives displayed. One said, "Don't you realize that outside air temperature can be as low as minus 70 degrees on high-altitude flights? It would require extra fuel to heat the air so that it could be used in the cabin."

Here is what my informal survey revealed. The people who answered the phones at United and Northwest told me that 100% of their air is recycled.

American told me they use 50% fresh and 50% recycled. No one (not even supervisory personnel) at Delta could answer my question after almost a half hour on the phone. I finally looked at their website while I was waiting and informed the supervisor that her airline uses 50% recycled air.

Delta's website states, "The air you breathe in the airplane cabin is 50% fresh from outside the aircraft and 50% recycled. This re-circulated air is drawn through High Efficiency Particulate Air (HEPA) filters prior to returning to the cabin. This system results in a total air exchange within 2-3 minutes (20-30 times each hour). This is more frequent than in homes and office buildings." Right, Delta, but in homes and office building people aren't packed shoulder-to-shoulder like sardines. And if your filters are so efficient, why do so many people get sick after flying?

I spoke to about a dozen people altogether at the four airlines. Most tried to convince me that it is technologically impossible to use fresh air at high altitudes. But one lady from American shared some interesting information with me. She told me that the Boeing 727's American used to use provided only fresh air to passengers, but that they have retired all their 727's. Here's a question for the airlines. If the 727 could use fresh air at high altitudes, why can't you engineer current aircraft to do the same? The answer is that obviously they can, but that they don't want to spend the money.

I had an interesting exchange with a woman from United. When I mentioned that the airlines will likely be on the wrong end of numerous lawsuits from people who get SARS, she said, "You know what? We'll probably be out of business before they can sue us." When I told her I'd like to quote her, for some reason she refused to give her name.

Anyone who flies and is even mildly observant will have noted that airlines are far more concerned about the safety of their personnel than that of their passengers (protestations that "Passenger Safety is Priority Number One" notwithstanding). All you need to do is look at the simple lap belts provided to passengers, and compare them to the double- cross-chest-plus-lap-belt restraints provided for pilots and flight attendants. So it should come as no surprise that the pilots on your flight are not breathing the same air that you breathe. The linked article below on reveals that pilots are provided a separate air supply with a greater flow rate. If there is no problem, as the airlines claim, why don't the pilots breathe the same air as the people who pay their salaries?

Lest you think me an alarmist, consider these facts. Flight attendants from more than twenty U.S.-based airlines, represented by the Association of Flight Attendants (AFA), are strongly pressing members of Congress for better standards governing cabin air quality. And the National Academy of Sciences is conducting a cabin air quality study, as required by congressional legislation.

In the second article listed below under "Links", there is a subtitle, "Who Is at Risk For SARS?" The answer, in part, is, "People who have had direct close contact with an infected person, such as those sharing a household with a SARS patient." There is danger of infection from just being in the same household? How about sharing a crowded airline cabin and breathing the same air as the SARS patient?

I suggest that everyone who must fly get one of those little masks that the Japanese wear. When people on your flight ask why you are wearing it, tell them, "I don't want to breathe the recycled air the airline uses in the cabin."

Better yet, hang a sign around your neck for those passengers who are too polite to ask you why you're wearing a mask:
"Danger! This airline recycles air instead of providing safe, fresh air for us to breathe."

We need to let the airlines know that we won't fly on any flight that recycles air that has been breathed, coughed in and sneezed in by hundreds of other passengers. They need to get their economic priorities straight. Yes, it will cost more fuel to provide fresh air to their passengers. It would be worth that cost to prevent the spread of colds, flu, pneumonia and other common respiratory diseases. The advent of SARS, with its risk of death, makes the consideration of the cost of fuel even less important.

NOTE: I seldom do this, but I feel this article is so important that it should be forwarded. In addition to forwarding it to your friends and colleagues, let me suggest that you contact the airlines listed below (and others on which you fly) and express your concerns about airline cabin air quality.

It does not have to do with flow. It's related to partial pressure of oxygen, and is why people can become hypoxic at higher elevations and altitude. While the ratio of gases is the same, what one breaths differs do to pressure.

While the ratio of gases is the same, what one breaths differs do to pressure.

Okay. I had the impression from your #33 "room air at sea level was 21% oxygen, but in Denver it was closer to 25%." that you didn't understand this.

The danger (if any) is from the person sitting right in very close proximity to you. It doesn't matter if the air is outside air or recirculated air.

Yep. The sneezer with no tissue or the guy who coughs into his hand...but there's a much worse hazard - everything that individual touches that you touch is a potential hazard if you aren't careful to wash hands frequently enough, which sometimes is impossible. The doorknob on the restroom is one of the worst. Doors on carryon bins, handrails, etc, etc...hey, it's a germy world out there!

...everything that individual touches that you touch is a potential hazard if you aren't careful to wash hands frequently enough, which sometimes is impossible.

True. The alcohol gels are somewhat effective.

I'd say do that look-up. That 25% figure is just plain wrong. Oxygen concentration, adjusted for pressure, temperature, and humidity, approaches the constancy of the force of gravity.

Another big problem in modern jets is that the humidity approaches zero percent, which dries out your sinuses even if you're drinking water like mad. Dry sinuses are much more accomodating to sinus infections &c.

Oxygen concentration

Exactly. The decrease in atmospheric pressure changes the concentration in a given area. It had to be considered and compensated for with respect to oxygen therapy. Medically, when speaking about oxygen that is being breathed in, it is understood that when using percent, one is refering to the partial pressure. Someone breathing "room air" in Denver isn't getting as much oxygen as someone at sea level. Did you read my other posts? The original post I replied to made it sound as if the same partial pressure of oxygen was available at 39,000ft.

I wonder if all your "facts" are as "true" as this? Truth is, planes must be pressurized because air above ten thousand feet provides minimal oxygen. (Even mountain climbers routinely must take oxygen.)

Sorry, ask anyone with ANY aviation background and they will tell you exactly what I said. That is why I responded to this ridiculous article - the facts are so obvious, yet people know very little about the issue. The fact is NO AIRLINERS FLYING TODAY PUT OXYGEN INTO THE CABIN IN FLIGHT. NONE, NADA, ZIP! They ARE pressurized, which is what I said - they are do NOT add oxygen. The reason is quite simple - compress (pressurize) the air back toward a pressure closer to sea level (in most cases, around 8,000 feet) and you will arrive at the proper sustainable oxygen content.

Excuse me??? If you really are a pilot I hope I never fly with you.

Well, it is a good thing that you do not fly yourself if you do not know the basic science of the atmosphere. The fact is, what I stated is EXACTLY correct. The oxygen content of the air at 39,000 feet is EXACTLY what it is at sea level. What is lacking is PRESSURE. Bring the pressure back toward sea level and you have the oxygen needed to sustain life.

Considering the fact that I have been an airline pilot for 23 years, I would imagine you may have flown with me before... and if you did you arrived safely - just like the tens of thousands of people I have carried.

If less planes need to fly, then less "Pilots" are needed to fly them. You aren't worried about your employment are you?

Actually, I do have an agenda - but not what you think. My agenda is to "out" idiots that know nothing about aviation making it sound like they do. The article has so many factual faults with it, it is silly.

Example: the author states that "727's used fresh air" - as if the systems are different on a 727 from a modern 737. They are essentially the SAME. NO, (I repeat NO) jet airliners pumped "fresh air" into the cabin as the author implies - they simply LEAKED more. There are "high flow" settings in modern airliners that match or exceed whatever a 727 did. The point is that any air that is shared is a problem. So, there MAY be SARS a problem flying on airplanes - just not the silly one the author makes). The author makes it sound like the airlines could FIX this and they choose not to. Those big bad airlines who want everyone to get SARS...

I apologize for questioning your veracity. That being said, you're post was not a good explanation and it appeared ingnorant and misleading. By saying that airlines do not provide oxygen, and there is ths same amount of O2 at 39,000ft, it sounded like you were saying there is the same oxygen inspired inside as out. It would have perhaps helped if you said that cabin air is not enriched. My husband who is a professional pilot thought it was misleading also, but was better than me at disecting what you had to say about recirculating air. It gave rise to a story about a 747 that had it's tail blown off. He doesn't post on FR though :(

as if the systems are different on a 727 from a modern 737. They are essentially the SAME. NO, (I repeat NO) jet airliners pumped "fresh air" into the cabin as the author implies - they simply LEAKED more.

My husband says you don't appear to understand the system. (That's the nice version of what he said). He'd also like to know if you know what an outflow valve is and it's purpose, as well as how air gets in that "leaks out." I've got diagrams in front of me of the Cabin Air Distribution System for a 727. Let me quote the manual

The advanced electronic pressurization system maintains cabin pressure by electronically governing the flow of air through a single main cabin outflow valve.

Thus, it is not simply leaking out of the plane.

My husband says you don't appear to understand the system. (That's the nice version of what he said). He'd also like to know if you know what an outflow valve is and it's purpose, as well as how air gets in that "leaks out." I've got diagrams in front of me of the Cabin Air Distribution System for a 727.

It is virtually impossible to overpressurize an aircraft at 39,000 feet - the outflow valve does indeed permit outflow at lower altitudes, but I can assure you at FL350 or above, the outflow valve remains virtually shut. ESPECIALLY on a Boeing 727. The ourside air comes in through the packs intakes - and at altitude it replaces what leaks out to maintain pressure.

I fly a Airbus A320, and the outflow valve is visible on my lower ECAM at cruise all the time. When toilet flushes creates a pressure bump that is visible because it uses part of the bleed system. In other words, the bleed is working in a stable environment at altitude, and even the slightest change has to be caught or the cabin descends.

Maybe your husband needs to watch an outflow valve work in flight.

By saying that airlines do not provide oxygen, and there is ths same amount of O2 at 39,000ft, it sounded like you were saying there is the same oxygen inspired inside as out.

Actually, what you thought I said is correct. The oxygen is EXACTLY the same percentage at 39,000 as at sea level. What is lacking is NOT oxygen, but pressure. Many average airline passengers think that we bring air in from outside and add oxygen to it. We do NOT. There is NO oxygen added at all - all that is needed is IN the air already. If airlines had to provide oxygen to the passengers I can assume you we would not be in business today because of the cost.

Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.