Remember “certainty"? That feeling of knowing what is happening and what will happen next? Me neither. Yet many of us are looking for shreds of certainty regarding seemingly simple questions like, “Is it safe or responsible to get on an airplane right now?”
While researching a detailed article on air travel safety, I spoke with an infectious disease control expert, dived into scientific papers, compared airline responses and finally came to this answer: Flying during the pandemic is not as risky as we once thought, but many unknowns remain.
What we know: Ventilation matters
I came away from my research very certain of one thing: Ventilation matters. Spending time with others in a cramped, poorly ventilated space is a bad idea.
“So … wouldn’t air travel be a terrible idea?!”
That’s what I thought going into this. As a frequent world traveler, I’ve long attributed my illnesses to the many hours I spend on aircraft. It makes sense: Flying involves sitting extremely close to dozens of strangers for hours at a time.
But I was wrong. (At least, I’m somewhat certain that I was wrong. I could still be wrong that I was wrong.) Despite their reputation for recycled air, commercial aircraft actually seem to offer excellent ventilation.
The Centers for Disease Control and Prevention website says that “most viruses and other germs do not spread easily on flights because of how air circulates and is filtered on airplanes.” This would qualify as “certainty” under normal circumstances, but the CDC repeatedly undercut its reputation this year by changing its mind on whether the disease is airborne. So I was a bit … circumspect … of this broad claim about the safety of air travel.
I expressed this concern to Molly Hyde, a board-certified infectious disease expert. She allayed some of my more conspiratorial fears. “Overall, this system of ventilation [on airplanes] is as good as, or better than, most other ventilation systems in public indoor spaces,” Hyde said.
Then I read a study commissioned by many federal agencies that demonstrated the effectiveness of air cabin ventilation systems (along with face coverings) at suppressing transmission onboard. The study involved strapping a nightmarish, faux-virus-spewing mannequin into an airplane seat and measuring the spread of aerosols to nearby seats. The conclusion: The pretend virus didn’t make it far before the aircraft ventilation system filtered it out.
So there are three sources of information — the CDC, a practical study and an expert — all suggesting that the ventilation systems on aircraft are better than I assumed.
“So flying is definitely safe?”
What we don’t know: Plenty
There’s just one small question: How many people are actually getting infected from air travel? That is, of the million or so people now passing through U.S. airport security every day, how many are then testing positive for COVID-19? Put another way: Of the people testing positive, how many had traveled by air? In other words: What is actually happening?
OK, maybe it’s not a small question.
Yet, astonishingly, the answer seems to be that we have no idea. Whether this is due to poor contact tracing, poor health data management or some other bureaucratic pratfallery, I have no idea. But the fact remains that no good publicly available data can address this crucial point: Are people getting sick from flying?
To illustrate why this is so frustrating, let’s take a step back — way back — to Dickensian London and the founding of modern epidemiology. The story goes like this: Nobody at the time understood cholera or how it was transmitted until an enterprising physician named John Snow placed the known cases of cholera on a map of London and saw that they centered around the city’s wells, including the now-famous “Broad Street pump.” Snow then knew something about how cholera was transmitted: by water.
Fast-forward to 2020: Computers exist, a pandemic is raging and people are flying — yet no modern-day John Snow seems to be plunking the data into Excel to see whether air travel poses above-normal infection risks.
In other words, we have plenty of hypothetical information about how the virus is transmitted, how important ventilation is and how well airplane ventilation performs, but we have no idea how this hypothetical rubber meets the road of actual COVID-19 transmission.
Risk, reward and eggs
Are eggs healthy to eat?
I’ve been trying to get to the bottom of this question for years. In my long-lost youth, experts warned that the cholesterol in eggs caused heart disease and premature death. Then some other health experts came along and exonerated eggs, blaming sugars and other refined carbohydrates instead. These days everyone seems to live in their own makeshift belief system regarding eggs.
(I’ve decided that eggs are probably the healthiest food you can eat. Check back in a few decades to see how that pans out.)
The point is: We all want certainty. We want to hear that either airplanes are totally safe and we can go back to our old travel habits, or that they’re utterly dangerous and we should stop flying altogether. Unfortunately, the evidence affords no absolute certainty.
What does that mean? In my view, it means adjusting my risk-and-reward thinking when planning air travel. If I have a very good reason to travel (reward), then this could outweigh the danger of infection to myself or others (risk).
Flying during the pandemic is a lot like eating eggs. Though we originally thought it was a terrible idea, now many experts seem to think that it's relatively safe. The biggest difference is that eating eggs can harm only your own health, while contracting the virus when traveling can spread it to others. Personally, I'll wait for more conclusive evidence that flyers are not contracting COVID before rushing back to the skies.
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