The Boeing 787 Dreamliner

Our previous article,  9 Threats To Your Health in 2017, provides an overview of challenges to your good health. Here, we introduce an issue concerning airline passengers: a toxic contamination of cabin air during a flight from a ventilation system defect, exposure to cabin pesticide spray, or both.

Ventilation System Defect

Researchers are investigating a safety defect in the ventilation systems of jet aircraft. This issue involves faulty seals and design in most aircraft (all except the Boeing 787 Dreamliner and Airbus A350), contaminating the "bleed air" drawn off at the engines to pressurize and ventilate aircraft cabins.

Contamination of the bleed air used to pressurize and ventilate aircraft cabins is of concern due to the potential health and safety hazards for passengers and crew. Reference

While substantial variations were found in frequency of incidents, it was found that the contamination events were widely distributed across nearly all common models of aircraft. Reference

Jet aircraft other than the Boeing 787 Dreamliner and Airbus A350 have "fume events" that may cause brain damage in crew members and passengers, a condition that some researchers call Aerotoxic Syndrome. 

In modern aviation, so-called fume events such as exposure to an unknown mixture of chemicals introduced into the aircraft cabin with bleed air drawn off at the engines may occur. Human exposure may result in (neuro)toxic symptoms described as so-called "aerotoxic syndrome." Reference

Aerotoxic Syndrome

Jet Fuel Toxins

Aerotoxic Syndrome has some similarities to neurotoxicity caused by heavy exposure to diesel and automobile engine fumes. However, jet fuel includes additives that are toxic to brain and other nerve tissue. One such additive is tri-o-cresyl phosphate, a potent neurotoxin.

Flight crews complain of illness following a fume event in aircraft. A chemical in jet engine oil, the neurotoxicant tri-o-cresyl phosphate, after metabolic activation to cresyl saligenin phosphate makes a covalent adduct on butyrylcholinesterase (BChE). Reference

Syndrome Symptoms

The symptoms of Aerotoxic Syndrome include cognitive dysfunction (problems with perception, memory, judgment, and reasoning), headache, and depression.

Clinical findings confirmed prominent symptoms of an intoxication, including headache, cognitive difficulties, and neurological disorders, among others.... The observed symptoms may be linked to known chemical compounds in fume events. Reference

In aircrew we found significantly more self-reported cognitive complaints and depressive symptoms, and a higher number of tests scored in the impaired range compared to the control group. Reference

Brain Damage

Highly sensitive studies on brain structure and function indicate that brain damage accounts for the symptoms from breathing in toxic jet engine fumes.

We observed small clusters in the brain in which white matter microstructure was affected. Also, we observed higher cerebral perfusion values in the left occipital cortex, and reduced brain activation on a functional MRI executive function task. The extent of cognitive impairment was strongly associated with white matter integrity, but extent of estimated number of flight hours was not associated with cognitive impairment nor with reductions in white matter microstructure. Reference

Notice that the degree of brain dysfunction does not necessarily depend on accumulated flight time. Variations in individual susceptibility to nerve damage from toxic exposure are due to individual differences in the body's ability to detoxify harmful chemicals. 

Therefore, Aerotoxic Syndrome is not only a problem for flight crews. Many passengers complain of cognitive dysfunction, depression, and other symptoms following air travel but likely attribute them to jet lag.

Aircraft Cabin Pesticide Spray

Aircraft cabin pesticide spray is another potential exposure to known neurotoxins. Although flight attendants are the greatest risk of exposure, passengers with known or unknown chronic disease typically have impaired detoxification mechanisms that increase susceptibility to poisoning.

Aircraft cabin disinsection is required by some countries to kill insects that may pose risks to public health and native ecological systems.... Preflight spray posed 2.0 and 3.1 times higher pesticide exposure risk levels for flight attendants in disinsected aircraft cabins than top-of-descent spray and residual application, respectively. Reference

Also, see  Aircraft Disinsection Requirements of the US Department of Transportation. 

Recommendation

Since exposures to toxic chemicals extend to all environments, not just aircraft cabins, we recommend the regular use of supplements that assist the body's natural detoxification mechanisms.  See  Detoxification Support.

About Horton Tatarian

I’m a biochemist who examines scientific findings on health and disease. My degree in biochemistry is from U.C. Berkeley. UCLA School of Medicine granted an M.D. degree in 1974. Since then, independent research prepared me to advise clients on natural ways of self-care.

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