Jet fumes, crowds of people in confined spaces, constant cleaning activities, toilet usage, and even construction—these are just a few things that are affecting the air quality inside airports and airplanes every day. These factors are also the reason why Camfil air filters are hugely beneficial to air travelers and aviation industry workers.
Fortunately, most airports and airplanes are now outfitted with a type of air filtration system designed to protect the health of passengers and staff. But it wasn’t always this way; in fact, only recently have we learned about the dangers of poor indoor air quality inside aircraft. And for many airline staff, its effects hit close to home.
Explaining Aerotoxic Syndrome on Airplanes
Take aerotoxic syndrome, for example. Coined in 1999 by a team of medical researchers composed of Dr. Harry Hoffman, Professor Chris Winder, and Jean-Christophe Balouet, aerotoxic syndrome was a term used to describe the negative long-term health effects of exposure to contaminated cabin air. By publishing their findings in a report, the team recommended taking a closer look into the brewing health crisis for frequent flyers, pilots, and cabin crew.
“Aerotoxic syndrome is an illness resulting from prolonged exposure to contaminants commonly occurring inside passenger airplanes,” notes Charlie Seyffer, Manager of Marketing & Technical Materials at Camfil USA. “Its effects can be long-lasting and life-threatening, especially for pilots, cabin staff, and frequent air travelers.”
Aerotoxic Syndrome and its Links to Indoor Air Quality in Aircraft
Since the 1950s, airplanes have been designed to use a “bleed air” system to filter air through cabins. Air passes through the engine compressor, also known as the engine’s cold section, before being sucked into the air-conditioning system and mixing with the recirculated cabin air. Indoor air quality problems happen when the oil that lubricates the engine heats up, resulting in emitting chemicals that leak back through damaged or inefficient seals into the compressor, and from there, back into the cabin air.
Under normal circumstances, the air filters inside airplanes do a pretty good job of removing gaseous pollutants, particulate matter like dust and soot, as well as bacteria and viruses. But, leaks can happen, and when they do, they’re usually identified by the presence of smoke or what seems to be the smell of dirty socks. These leaks are known as fume events, and, according to Dr. Hoffman and his team, they can cause acute toxicity, with symptoms that include:
- Runny nose
- Sneezing
- Nausea
- Headaches
- Memory loss
- Muscle weakness
Note that these symptoms can occur after exposure to big leaks. But according to cabin crew and pilots, their constant exposure to silent and odorless seepages of contaminated air can be just as dangerous to their health.
Why Commercial Air Filters for Airplanes are Necessary
“Commercial air filters for airplanes, provide a necessary layer of protection against things such as jet fuel, de-icing fluids, jet engine oil, and hydraulic fluids among others, all of which are toxic and can affect air quality inside the aircraft,” said Seyffer.
While these chemicals usually stay within engines and aircraft equipment, their emissions can sometimes mix with cabin air due to seal failures, oil leaks, or fluid ingestion by the engine or the auxiliary power unit (APU), which is the small engine at the rear of the plane. In turn, exposing crew and passengers to a host of airborne contaminants.
In fact, there are dozens of smoke and in-cabin leak events documented each year, often linked to an instance of aircraft fluid leak. Fume events, on the other hand, happen much more frequently, and are linked to leaks of less critical aircraft fluid, said to happen hundreds of times a year according to independent reports.
At the time Dr. Hoffman and company conducted their study, it was estimated that aircraft fluid leaks and smoke events affected over 300 flights around the world each year, resulting in the pollutant exposure of more than 40,000 passengers and aircraft crew.
Unfortunately, the variety and concentrations of bleed air contaminants found in contaminated aircraft cabins in mid-flight can be extensive. Examples of common airborne contaminants found in the study include:
- Carbon monoxide
- Aldehydes
- Aromatic and aliphatic hydrocarbons
- Nitrogen compounds
- Esters
- Nitrogen oxides
Furthermore, certain aircraft models seem to be more prone to fluid leaks.
Preventing the Health Issues of Air Flight with Industrial Air Filters
Of course, you might be wondering if the need for industrial air filters is more important in airplanes than ordinary homes and buildings. While good air quality is obviously important in the latter, it’s even more so in the cabins of planes flying at altitude.
The reason for this is during mid-flight, aircraft cabins have lower oxygen levels—the amount of oxygen in the air becomes lower as altitude increases, whether traveling in a pressurized plane or climbing a mountain. The lack of oxygen forces healthy passengers and crew to increase their breathing rate—often without them knowing it at all. In terms of toxicity, this means that airline passengers and crew are inhaling more contaminated air, increasing their risk of developing an illness.
And according to some studies, exposure to polluted air begins the moment passengers and airline crew step inside airports.
Protecting Air Quality in Airports with High Efficiency Air Filters
In airports, the main sources of air pollution are diesel engine emissions from tractors and de-icing equipment, fuel emissions from refueling activities, and dust particles from asphalt, tires, and brakes. Pollutants from these activities, which commercial high efficiency air filters are designed to capture, are divided into the following categories:
- Polycyclic aromatic hydrocarbons (PAHs)
- Volatile organic compounds (VOCs)
- Inorganic gases
- Nitrogen oxides (NOx)
- Particulate matter (PM)
Inside the terminal, there’s an equal variety of pollution sources. For starters, the thousands of people that walk through the airport shed up to a million particles every minute—even more as their activity level increases, which is often the case as people rush to catch their flights or claim their baggage. Likewise, the clothes people wear and the luggage they haul around all contribute to indoor air pollution. These particles are easily removed by particulate air filters that usually have a particle removal efficiency of MERV 13 or higher.
Of course, you also have to consider the construction, maintenance, and cleaning activities that seem to be a constant factor in all of the world’s major airports. Things like construction materials, paints, solvents, cleaning chemicals, disinfectants, and even furniture all release volatile organic compounds (VOCs) into the air, putting the health of passengers and airport crew at risk. These items are considered gaseous contaminants and high efficiency industrial filtration removes these contaminants through the application of carbon or oxidizing filters.
A Final Word on Industrial High Efficiency Air Filtration Systems in Airports and Aircraft
The good news is that the aviation industry is finally acting on the problem of aerotoxic syndrome and pollution in airports. In 2017, British budget airline EasyJet announced that it would be outfitting aircraft with specially designed industrial air filtration systems to prevent toxic fumes from penetrating passenger cabins and cockpits. It’s a much-needed step in the right direction, what with the airline industry long denying the existence of aerotoxic syndrome despite the consistent stream of reports from the pilots, passengers, and flight attendants who have fallen ill, and even died, after long-term exposure to air inside aircraft.
For more than 50 years, Camfil USA has been a global leader in designing and manufacturing air filtration systems for airports around the world. To learn more about the importance of indoor air quality control in airports and airplanes, talk to Camfil USA. Also, explore our catalog of air filtration systems to learn more about our products.
Lynne Laake
T: 888.599.6620
E:Lynne.Laake@camfil.com
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