So you are concerned about flying with the corona virus purportedly in the air? If John Rappoport is right in his hypothesis that polluted air could be a cause of epidemic illness, you certainly have reasons to be concerned. Referring to a Yale study he states that the mixture of toxic elements with unknown synergistic effects in our sea-level air is unprecedented in human history, never mind the one on board aircraft. And it is well known that bad air quality brings on all kinds of lung infections including pneumonia, the illness attributed to the coronavirus, if there indeed is such a virus. It is less well known that aircraft are ideal breeding grounds for all sort of respiratory illness due to the lack of in-flight air. Vigorous recycling of at least 53 % at lengthy intervals assures it. It saves on fuel consumption thus increasing shareholders profit. Who cares that it increases the potential of spreading all sorts of illnesses through aircraft ventilation systems including the coronavirus bug, if it indeed exist.
The cambodiacapital.com thinks so, stipulating in February 2020 that polluted air could indeed be an important cause of the “Wuhan pneumonia” a.k.a. corona virus. Or it could be carried on particulate pollutants thriving on Earth as in heaven due to commercial aircraft air quantity and quality as provided by the airlines.
It is a well-known fact that because of the effects of high altitude on humans aircraft must be pressurized and supplied with artificial oxygen, air ventilation- and filtration systems. These systems usually are set to operate at between 6000–8000 feet above sea level. Until the early 80s, they supplied a 100% fresh air circulation to all cabins at about three minute intervals by pumping outside air through engine compressors into the aircraft and back outside through exhaust valves.
To save fuel engineers then designed an air-intake system where up to 53% of cabin air passes through filters to blend with fresh outside air before it’s re-injected into the cabins. On most aircraft the filters used to purify the air purportedly remove 90 to 95% of dust, bacteria, and viruses—but not gases and odors. They are also said to remove up to 99.99% of airborne contaminants 0.5 microns or larger. But many of those contaminants are said to be smaller than 0.5 microns. But how often these filters are changed to guarantee their proficiency is a mystery.
The amount of oxygen provided to passengers and cabin crew depends entirely on an airline’s generosity. One carrier instructed its Airbus pilots to select HIGH only if flight attendants reported to the flight deck in person complaining about difficulties breathing. In a nutshell, the 100% fresh cabin air circulated about every three minutes through aircraft manufactured before the 1980s was replaced by providing half-fresh and half-recycled air every six or seven minutes in newer aircraft. Air ventilation in itself corresponds to class compartments. The less air circulation the greater the reduction of oxygen to passengers and cabin crew, though they now have breathing stations in the galley areas. Cabin airflow going from front to back, first class passengers thus receive first class air its quality diminishing as it finds its way to the back. Pilots also lower air flow after meal service completion to increase it again roughly one hour before landing to assure economy class passenger and cabin crew are able to walk rather than crawl of board.
The Joint European Aviation Authority mandates that European carriers must provide each crewmember with no less than 10 cubic feet per minute (cfm) to enable them to perform their duties without “undue discomfort or fatigue.” The US Federal Aviation Administration (FAA) on the other hand finds 7.5 cfm more than sufficient. That cockpits have completely separate ventilation systems administering 100% fresh air at much higher volume to the pilots than that delivered to the peons in the back is rarely known. Thus there is blatant discrimination o/b aircraft in regards to the air to breath. The United States Academy of Sciences National Research Council measured that on full Boeing 747s during domestic runs pilots inhaled the luxurious amount of at least 150 cfm of 100% fresh air from their private system, whilst First- and Business class passengers received between 30 to 50 cfm of recycled air and those working or lounging in the high-density economy sections got less than 7 cfm for their breathing enjoyment. And when calculating fresh air-intake combined with recycling, air circulation and human carbon dioxide addition in-flight it translated into less than 5 cfm per person for those traveling in the back. Viruses thrive under those conditions. Low oxygen tension enhances Hepatitis C virus (HCV) replication so why not that of the corona virus, if it indeed exists?
So, now you know. It’s not your constitution unduly acting up when you exit the aircraft with a pounding headache and are pooped and ailing for days and weeks afterwards in particular after a longer flight. Those ailments are invisible gifts graciously extended by your courteous North American airline. And you ought to count yourself blessed if exhaustion and fatigue is all you suffer. Cabin- and cockpit crews suffer much worse, but of that another day.