Toxic Fume Leaks On Planes Making Both Passengers And Crew Horribly Sick

When you get on a plane, you know you run the risk of sitting next to a yapper, or you might encounter one of those sick freaks who goes to the bathroom barefoot. Heck, even though the odds of it happening are minuscule, you know there’s even the small chance the plane might crash. One thing you probably don’t expect, though, is to be poisoned by the air on board, leaving your brain looking like you just got ear-holed by Dick Butkus in his prime. And yet, it happens. In fact, it’s been happening for more than a decade, the Wall Street Journal reports.

The culprit is what’s known as a fume event, and it occurs when toxic fumes from jet engines make their way into the cockpit or cabin. It’s also made possible because the air you breathe on board is pulled through the engine via a system known as “bleed air” that’s used on essentially every modern commercial plane, aside from the Boeing 787. And while the WSJ found reports of fume events dating at least as far back as 2010, in recent years, they’ve been happening more frequently, with thousands of incidents reported — particularly on Airbus A320s. 

From the WSJ:

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.

While not all fume events lead to seriously debilitating injuries, it’s still a real possibility. Take Florence Chesson, a flight attendant for JetBlue, for example. After breathing air that she said smelled like dirty feet, she immediately felt like she had been drugged. “I felt like I was talking gibberish,” she told the WSJ. “I remember being very repetitive, saying ‘What just happened to me? What just happened to me?'” Her condition only got worse from there:

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.

Sadly, what happened to Chesson isn’t a completely isolated case, either, nor is it reserved only for pilots and flight crew. Dr. Kaniecki told the WSJ that in the last 20 years, he’s treated “about a dozen pilots and over 100 flight attendants for brain injuries” after they were exposed to toxic fumes. He also reportedly treated at least one passenger, described as “a frequent flier with Delta’s top-tier rewards status who was injured in 2023.”

If you ask the manufacturers, regulators and the airlines themselves, “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.” They’ve also blamed the health issues some have reported on “hyperventilation, jet lag, psychological stress, mass hysteria and malingering.” And when the WSJ reached out to Airbus, Boeing, the FAA and the European Union Aviation Safety Agency for interviews, all four declined. 

In a statement emailed to the WSJ, a Boeing spokesperson said, “The cabin air inside Boeing airplanes is safe. There is no indoor environment that is free from ‘contaminants.'” They also claimed research shows “that contaminant levels on aircraft are generally low and that health and safety standards are met.” Meanwhile, a JeBlue spokesperson told the newspaper, “We take nothing more seriously than the safety and health of our crewmembers and customers. While cabin air quality concerns are not isolated to JetBlue, we continue our work to identify policies and procedures to reduce and manage them.”

The FAA, meanwhile, says on its website that such incidents are “rare,” citing a 2015 review that suggested a rate of “less than 33 events per million aircraft departures.” At that rate, you would still see about 330 fume events in the U.S. every year, but as the WSJ discovered, in 2024, the 15 largest U.S. airlines reported more than twice that many. Perhaps more concerning is that they’re happening much more frequently. Back in 2014, “the Journal found about 12 fume events per million departures. By 2024, the rate had jumped to nearly 108.” 

Those are also just reported events. We don’t know how many incidents went unreported, potentially making the true rate even higher. Internal data from the International Air Transport Association, however, puts the rate at about 800 per million departures.

As previously mentioned, the Airbus A320 appears to be the largest contributor to the overall increase in fume event frequency. Last year, “the rate of reports on A320s had increased to more than seven times the rate on their Boeing 737 aircraft.” And between 2016 and 2024, JetBlue and Spirit saw fume events aboard their A320s jump a whopping 660%. The WSJ‘s analysis showed the sudden spike in incidents on A320s really began in 2016, when Airbus first began deliveries of its A320neo planes.

The A320neo’s new engines were more fuel-efficient than their predecessors, but they reportedly also used seals that degraded quickly, leading to more fume events. Airlines then began complaining, since those events were taking their planes out of service too frequently. Instead of improving the seals, Airbus reportedly changed the maintenance rules, no longer requiring an inspection and deep cleaning after every fume event, since it considered it a “minor comfort issue.”

To no one’s surprise, those changes to the maintenance rules led to more fume events, with one example cited by the WSJ of a single Spirit Airlines plane that experienced six reported fume events in the space of a month.

Ask the airline industry, and they’ll tell you there isn’t any evidence that fume events release enough toxins into the cabin to cause any lasting harm. However, a recent FAA-funded study tells a different story:

But a recent FAA-funded study found two chemicals that can: formaldehyde, a known carcinogen and neurotoxin, and tridecane, which can cause headaches and stupor. Another, an organophosphate called tributyl phosphate, was right at the limit, according to a Navy toxicologist’s review of the findings. The analysis assessed 129 chemicals of which 40 have yet to be given an exposure threshold in the U.S.

Researchers also said that a real-world leak of the same quantity of oil would likely produce significantly higher levels of toxic chemicals than they measured.

As Joseph Allen, an air quality specialist at Harvard, told the WSJ, “The chemicals exceed the worker threshold, which means they far exceed the threshold to the general public. It’s clear to me that there’s concerning data in these studies and it’s inappropriately downplayed.”

In an internal report issued after two Southwest planes dealt with bird strikes in 2023, the FAA also acknowledged how dangerous these events can be, claiming the strikes “exposed a design flaw in the aircraft’s engines” that caused several liters of oil to enter the air supply and “risked exposing pilots to potentially lethal concentrations of chemicals ‘at just 39 seconds.'” Instead of mandating a fix, the FAA simply told the airlines about the problem and “advised them to evaluate procedures and crew training before it mandates a permanent fix.”

Meanwhile, Airbus has reportedly identified a specific air vent that caused the vast majority of its fume events, and the fix will reportedly be ready to go in the first quarter of next year. However, it will only be available on newly built aircraft. Oh, and documents also reportedly show airlines have been pushing for that fix since at least 2019.

As long as this post already is, there’s far more in the original Wall Street Journal exclusive, so you’ll definitely want to give the whole thing a read.