New health concerns – and cancer link – over toxic cabin air breathed by 3.5 billion passengers each year

 July 27, 2017


In June 2017, a study was published in the World Health Organization journal Public Health Panorama – the first of its kind to look in-depth at the health of aircrew exposed to contaminated air during their careers.

Scientists examined of more than 200 aircrew with a “clear pattern” of acute and chronic symptoms said concluded there was a “clear link” between being exposed to the air on planes and a variety of health issues.

In May, the discussion of toxic cabin air was reignited after a Thomson Dreamliner was forced back to Florida after two flight attendants collapsed and passengers fell ill due to fumes.

Also, over the past year, three airline crews in Atlanta had emergency medical care after fumes on board made them sick.

Last fall, British Airways was accused of ‘shamefully’ downplaying serious toxic fume events.

How Does The Cabin Air Become Toxic?

It surprises people that the same jet engines that take you into the air, also draw in the air you breathe – It’s called bleed air. The engine’s oil has an additive called Tricdresyl phosphate, or TCP.  Tricresyl Phosphate poisoning is characterized by numbness of the legs and hands accompanied by weakness or paralysis of these regions, though all symptoms usually only occur after a latency period of 2-3 days.

Because warm air is needed for engine propulsion and for passengers to breathe, it was decided to combine the two and bring the air through the engine to heat it, then ‘bleed’ it off and pass it unfiltered into the cabin. It is this ‘bleed air’ that has been the cause of so much controversy.

There are seals in the engine intended to keep oil out but they require air pressure to keep the seal tight, and at times they allow contaminated air to pass into the cabin. If the seal is worn or faulty or if the oil is leaking, large amounts can pass into the air supply and these are known in the industry as ‘fume events.’

Facts About Bleed Air (from Aerotoxic Association)

  • Cabin breathing air on aircraft is taken directly from the engines and provided unfiltered to the aircraft. This is known as ‘bleed air.’
  • Bleed air is known to become contaminated with engine oils and/or hydraulic fluids.
  • Contaminated bleed air events have been recognized as occurring since the 1950s.
  • No aircraft currently flying has any form of detection system fitted to warn when these events occur.
  • Flight safety is being compromised by contaminated air events.
  • Crew and passengers have been reporting short and long term health effects as a consequence of exposure to contaminated air.
  • Contaminated air events are not rare and known to be under reported.

So why are passengers not being told?

Contaminated air in the cabin has long been an open secret among pilots and crews. The aviation industry has been accused of knowing about the problem for decades and doing little to tackle it.

The scientists behind the study are calling for the airline industry to change in the wake of their findings and begin to address an issue.

This week, Connecticut Senator Richard Blumenthal proposed new legislation to protect pilots, flight attendants, and passengers from this preventable public health problem.

Documents show that despite congressional inquiries, the Federal Aviation Administration has done little. Officially, the FAA does not take a stand and says more study is needed.

The flight attendants union says it’s working with Congress to require new fume sensors and filters on airplanes. Airbus, like Boeing, says its cabin air is safe.

Based on a 2016 study from Kansas State University, the flight attendants union estimates there are five fume events each day on airlines world-wide. Most are minor, but the union says there’s a risk.

A WSB-TV Atlanta investigation combed through FAA reports and found more than 100 possible fume events on commercial airlines in the past year. In nine cases, illnesses were reported. The reports filed with the FAA come from a variety of airlines and a variety of planes.

Toxic air should not be a cost of air travel. Given that those affected may suffer permanent ill health, the lack of action to address this problem suggests a lack of care on the part of the government and airlines for their passengers and staff.