Toxic cabin air may threaten passenger and crew health

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Despite industry claims that toxins in contaminated cabin air are harmless, medical and scientific evidence is proving otherwise following the OPIN-related death of British Airways pilot Richard Westgate.

Nervous system damage due to “organophosphate-induced neurotoxicity,” or OPIN, has been identified as a major contributing factor to the death of the 43-year-old non-smoker and non-drinker. Because Westgate authorized medical testing before and after his death, a trio of researchers has been able to conduct post-mortem testing that reveals the link between Westgate’s illness and contaminated cabin air.

Professor M.B. Abou-Donia of Duke University Medical School, lead author of the study, said the air transport industry has failed to recognize three aspects of organophosphate exposure, including combined exposure to multiple compounds, the cumulative effects of repeated exposure, and individuals’ genetic predisposition to toxicity.

Despite known toxicity of compounds found in engine oil fumes since the 1930s, airlines’ safety literature omits any warning of health threats caused by breathing contaminated cabin air. The rationale for doing such has been that toxin levels are too low to cause harm. The organization trying to address these matters is Global Cabin Air Quality Executive. Their head of research Dr. Susan Michaelis said there is no basis for a “harmless level” of inhalation for these neurotoxins.

“Most of the substances in the oils and fluids do not have set limit values/exposure standards and therefore for the industry to say all levels found were safe and below government-established levels is incorrect,” said Michaelis.

A 2009 health care professional guide for treating those exposed to contaminated cabin air partially funded by the FAA states that exposure to organophosphate contaminated air sometimes causes airline workers to develop acute or chronic health effects. Additionally, the European Commission Directorate-General identified issues with cabin air as a possible national health concern at a December 2013 conference in Brussels.

Despite this limited regulatory recognition of the issue, the industry has contested need for action, resulting in many cases of unreported toxic air exposures for passengers and crew. A 2014 Australian Transport Safety Bureau report ­revealed passengers and crew flying nationally were exposed to toxic fumes more than 1000 times over the past five years, even including emergency landings especially because of fumes.

All aircraft, excepting the “bleed-free” frame of the Boeing 787, are susceptible to contaminated air, as cooled air from off the engines can “bleed” into the cabin. When engine oil seals leak or fail, oil fumes contaminate the “bleed air”, which goes directly to the flight deck air supply systems. That air is used to heat cabin air, pressurize altitude and even drinking water.

Organophosphates like TCP, found in contaminated cabin air, cause demalination of nerves, Professor Abou-Donia has shown, which lead to various symptoms, including severe headaches, constant pain and insomnia. TCP is even more toxic when heated to high levels, as occurs in-flight.

David Learmount, operations and safety editor of Flightglobal, compares the situation to the tobacco industry’s successful denial of a connection between smoking and lung cancer for decades. “Biochemistry/neurology are such complex medical fields that the lawyers can still find ways to stall the arguments, because the burden of proof is with those who are bringing the case, not with the industry, which says there is no case to answer,” said Learmount, who has been sounding the alarm about this issue on his safety blog.

Exxon Mobil spokesperson Christian Flathman responded to questions on whether its oils were safe for inhalation by pregnant women by citing a 2003 study on toxicity, which says that Mobil jet engine oils are safe “under normal conditions of use and with appropriate handling practices”. Flathman did not clarify whether Exxon Mobil considers events leading to contaminated air leaks as ‘normal conditions of use.

Air filtration company Purafil could filter out contaminants, according to director of business, Americas Unit, Chris Moon. He says, “Typically if you can identify and capture a contaminant, then you can filter it. Then it becomes a matter of – is it worth filtering, or is there another way to resolve this?”

Liebherr Aerospoace has designed and is currently testing an all-electric bleed-free air conditioning pack with Airbus, which would prevent any engine air from entering the cabin. Results are expected as part of the Clean Sky 2015 environmental initiative.