[…] After months of worsening symptoms, Chesson was diagnosed with a traumatic brain injury and permanent damage to her peripheral nervous system caused by the fumes she inhaled. Her doctor, Robert Kaniecki, a neurologist and consultant to the Pittsburgh Steelers, said in an interview that the effects on her brain were akin to a chemical concussion and “extraordinarily similar” to those of a National Football League linebacker after a brutal hit. “It’s impossible not to draw that conclusion,” he said.
Chesson’s experience is one dramatic instance among thousands of so-called fume events reported to the Federal Aviation Administration since 2010, in which toxic fumes from a jet’s engines leak unfiltered into the cockpit or cabin. The leaks occur due to a design element in which air you breathe on an aircraft is pulled through the engine. The system, known as “bleed air,” has been featured in almost every modern commercial jetliner except Boeing’s 787.
The rate of incidents is accelerating in recent years, a Wall Street Journal investigation has found, driven in large part by leaks on Airbus’s bestselling A320 family of jets—the aircraft Chesson was flying.
The Journal’s reporting—based on a review of more than one million FAA and National Aeronautics and Space Administration reports, thousands of pages of documents and research papers and more than 100 interviews—shows that aircraft manufacturers and their airline customers have played down health risks, successfully lobbied against safety measures, and made cost-saving changes that increased the risks to crew and passengers.
The fumes—sometimes described as smelling of “wet dog,” “Cheetos” or “nail polish”—have led to emergency landings, sickened passengers and affected pilots’ vision and reaction times midflight, according to official reports.
Most odors in aircraft aren’t toxic, and neither are all vapors. The effects are often fleeting, mild or present no symptoms.
But they can also be longer-lasting and severe, according to doctors, medical records and affected crew members.
The cause of fume events isn’t a mystery. Airbus and Boeing, the two biggest aircraft manufacturers, have acknowledged that malfunctions can lead to oil and hydraulic fluid leaking into the engines or power units and vaporizing at extreme heat. This results in the release of unknown quantities of neurotoxins, carbon monoxide and other chemicals into the air.
[…]
Manufacturers, regulators and airlines have said these types of incidents are too infrequent, levels of contamination too low and scientific research on lasting health risks too inconclusive to warrant a comprehensive fix. In some cases, they have attributed reported health-effects from fume exposure to factors including hyperventilation, jet lag, psychological stress, mass hysteria and malingering.
Internally, industry staffers have flagged their own fears about the toxic makeup of engine oils.
[…]
The individual airlines mentioned in this article noted their commitment to the safety of their passengers and crew, and said they follow the protocols established by the FAA and the manufacturers of their planes.
[…]
The FAA on its website says the incidents are “rare” and cites a 2015 review that estimated a rate of “less than 33 events per million aircraft departures.” That rate would suggest a total of about 330 fume events on U.S. airlines last year.
In reality, the FAA received more than double that number of reports of fume events in 2024 from the 15 biggest U.S. airlines alone, according to the Journal’s analysis of service difficulty reports for flights between 2010 and early 2025. The rate has soared in recent years. In 2014, the Journal found about 12 fume events per million departures. By 2024, the rate had jumped to nearly 108. (Read more about how the Journal conducted its analysis.)
In a statement, the FAA attributed the increase in part to a change in its guidance for reporting fume events, although that revision was only implemented in November of last year.
[…]
The FAA doesn’t have a formal definition of a fume event and the service reports often don’t indicate the severity. In its review, the Journal mirrored the industry’s practice of relying on crew reports of specific odors and associated maintenance reports. Changes in crew awareness could impact reporting rates.
The actual rate is likely far higher, as crews don’t always report incidents to their airlines, which likewise don’t report all instances to the FAA. A review of internal data by the airline lobby International Air Transport Association, calculated a total rate of 800 per million departures in the U.S., according to an internal document from a member carrier.
The Journal’s analysis suggests that the growth is driven by the world’s bestselling aircraft: the Airbus A320. In 2024, among the three largest U.S. airlines with mixed fleets, the rate of reports on A320s had increased to more than seven times the rate on their Boeing 737 aircraft.
[…]
The Journal’s analysis shows incidents began climbing in 2016, the year Airbus started delivering its new A320neo, what would become the world’s fastest-selling model. It boasted a new generation of fuel-efficient engines, including one that was plagued by rapidly degrading seals meant to keep oil from leaking into the air supply.
Under pressure from airlines who complained that fume events were keeping aircraft out of service for up to days at a time, Airbus loosened maintenance rules, according to a review of internal documents and people familiar with the changes.
For example, under the old guidelines, Airbus typically required an inspection and deep-clean after a fume event. Under the revised rules, if the smell wasn’t strong and hadn’t occurred in the last 10 days, airlines wouldn’t need to take immediate action.
[…]
This sounds like the kind of health risk ignoring that went / goes on in Tobacco companies and impact sport head injury risk
