A former airline pilot and a flight attendant both say their lives were changed forever when they inhaled toxic fumes that entered an aircraft cabin, which they say caused lasting harm to their health.
In an interview with ABC News, David Hill, a former airline pilot, described a flight six years ago during which he says he and the entire crew and some passengers reported feeling ill.
Denise Weiss, then a flight attendant, was on that flight.
“It was a flight of confusion ... I felt intoxicated, I felt a headache that was like no other headache, my eyes were bloodshot, I felt intoxicated and obviously I had had nothing to drink and didn't understand why I was feeling that way,” she said.
She added: “My whole life changed. My health to this day is not the same.”
Hill and Weiss say they were both exposed to a neurotoxin that leaked into the cabin air during the flight, and, they told ABC News, this was a hidden risk passengers should know about.
Effects 'Ended My Career,' Former Pilot Says
Many people don’t realize that air used to pressurize the aircraft cabin is redirected from the engines. It’s known as bleed air.
In the engine’s oil is usually an additive that contains tricresyl phosphate, or TCP, which reduces wear on engines and improves thermal stability of the oil. TCP is a toxin. If there’s a leak due to a broken seal or a maintenance issue, oil containing TCP can leak into the engine and the air released into the cabin can contain fumes from that chemica, creating an odd smell that’s been compared to the smell of dirty socks.
The flight attendants’ union – the Association of Flight Attendants-CWA -- has asked airlines to better protect the public and airline crews from toxins that could enter cabins from engines by installing sensors that would detect neurotoxins in the air and filters that would capture the toxins.
There have been reports of airline passengers and crew taking ill on flights after noticing an unusual smell in the cabin.
Weiss said her doctors told her she’d suffered damage as a result of the suspected toxin, recalling that she was told she had “central nervous system damage from the chemical.”
The former flight attendant said she takes medication for headaches.
“If I don't take the medication, I wouldn't be able to function, there’s no rhyme or reason as to one day I can function, if you will, normally and walk across the street or walk from one store to another in the mall and there’s some days I cannot even go to my mail box without even being in pain,” she said.
People who inhale enough of the chemical could suffer memory loss, balance issues and headaches, experts say.
Hill, the pilot who says he was exposed to the chemical during a flight, told ABC News that his symptoms – including short-term memory loss and balance -- were so bad that the FAA said he was no longer safe to fly.
“That ended my career,” he said.
How Frequent are 'Fume Events'?
There is a so-called fume event on one out of an estimated 35,000 flights across the country each day, according to the union. Most of the fume incidents don’t cause problems.
Boeing and Airbus, the two main aircraft manufacturers, said in separate statements that the cabin air in their aircraft is safe. Boeing also noted that it was aware of efforts to enhance sensors to detect airborne contaminants but stated: “Such technology must be demonstrated to be highly reliable before it can be safely incorporated on aircraft.”
Airbus noted that HEPA (high-intensity particulate air) H13 filters were standard on all its aircraft. But experts say those filters can capture some – but not all – of the toxin.
And Airlines for America, the industry group, said in a statement: “Frequent studies over the years have consistently concluded that cabin air meets or exceeds health and safety standards.”
In a statement the FAA said the air on jets on the vast majority of flights is safe but it also said that, in the rare event of a mechanical failure, the cabin “may contain contaminants.” Airlines are required to report fume events to the FAA.
Using air monitors and swabs, ABC News tested the air and several areas in the cabin on five different flights operated by four separate airlines. Every swab picked up traces of TCP, which could be due to accumulation from several flights.
The air monitors didn’t detect TCP but they did find evidence of small amounts of jet engine oil, which would suggest a leak.
While oil leaks and fumes in the cabin are possible, experts – and even people who say they have been affected – say the risk to passengers is low.
Asked how people could protect themselves, Hill replied: “There is no way.”
Added Weiss: “You should be worried about this, you should be aware of it.”