It showed when I was most likely exposed to COVID


Denver — Seat 10D with passengers packed in the aisle Carbon dioxide detector Balanced on the lap.

Someone has no choice but to tremble a little every time Coughing and sneezing Upon boarding, the detector reading will steadily increase from about 800ppm to over 1,600ppm.

According to experts, the level of carbon dioxide in the indoor air is Easy proxy I wanted to see what my potential risk was about potential COIVD-19 exposure, and because the mask was voluntary on the plane and international arrivals no longer needed to be tested.

Carbon dioxide in the open air is usually less than 400 ppm, and airplane CO2 levels never reach levels that are considered unhealthy at all, but numbers indicate that they are exposed to the coronavirus. I can’t help but touch the mask for peace of mind.

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USA TODAY reporter Trevor Hughes on a United Express flight to Dulles International Airport on April 18, 2022.

USA TODAY reporter Trevor Hughes on a United Express flight to Dulles International Airport on April 18, 2022.

On this flight, I’m wearing a mask to visit my older parents in Vermont.When I last visited I Last mandatory masked flightAnd since then I have taken several flights.

Nationally, about 300 people die from COVID a day. Rapid tests are now widely available, but they only measure if you are infected. There is no way to know about the people around you. Especially if many people don’t seem to care if they are infected or how they affect my parents and other endangered communities.

That’s where the CO2 detector comes in. I bought a $ 140 KOPUO tester from Amazon. According to experts, this is one of the cheapest but most accurate detectors. The cheaper ones use a different measurement system, but it can be inaccurate if many hand sanitizers are used around it.

Why measure CO2?

According to the University of Colorado at Boulder, areas with high CO2 levels may have an increased risk of infection, but areas with low CO2 levels can be considered safer. Professor Jose-Luis Jimenez..

Jimenez Particle and gas expert Moving around in the room, he tested many cheap CO2 detectors and found that many were very accurate compared to laboratory-grade equipment.

“It’s the only thing we’ve found to estimate that we have this information,” Jimenez said. “It’s not perfect because everyone exhales carbon dioxide, but not everyone who exhales has a COVID.”

Jimenez and his colleagues found in the library that the risk of COVID infection tripled when human influx doubled CO2 levels from 800 ppm to 1,600. Also, when Jim’s CO2 levels drop from 2,800 ppm to 1,000, the risk of COVID-19 infection is reduced by 75%.

Of course, his model needs special attention when it comes to masks, planes and HEPA filters. HEPA stands for “High Efficiency Particle Air” and most large aircraft manufactured by Boeing and Airbus are equipped with HEPA. HEPA filters are effective in removing dust, pollen, bacteria, and virus particles in the air, but they do not remove carbon dioxide because it is a dissolved gas containing much smaller molecules.

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Studies conducted by the federal government, airlines, aircraft manufacturers, and other researchers conclude that air travel has a relatively low risk of COIVD infection, primarily because HEPA filters remove virus particles. I am. However, this is only relevant if the aircraft is pumping air through a filter. According to Airbus, the system completely replaces the air on board every few minutes during flight.

Measurement of CO2 levels during flight at the airport

My measurements showed that CO2 levels soared while boarding the Airbus A319 to Vermont, but little changed on the flight back to Denver. This is because both flights are equally full and the pilot or ground crew is doing something else at the time of boarding, even though I was sitting in about the same place in both directions, refreshing the air. It shows that it was kept.

United Airlines did not respond to requests for comment on specific policies, but said, “Aircraft always have fresh air. The main advantage of HEPA is that a large amount of outside air circulates inside the aircraft, so if it is in the air. Anyway, a boarding bridge on the ground. “

At the Denver International Airport terminal, CO2 levels were relatively constant at around 800 ppm, and it was comfortable to remove the mask to turn McDonald’s Hash Brown into a wolf. The level of the airport train to the concourse reached about 1,000 ppm, but when I was sitting at the gate, I was wondering how few men washed their hands after using the toilet. That idea also made me tremble.

On board, CO2 levels reached 1,520 ppm when the flight attendants closed the boarding gate, rose to about 1,800 when the pilot appeared to have turned on another ventilation system, and when taxiing to the runway. It dropped to about 1,600 and then bounced back to 1,900. When approaching the end of the runway for takeoff.

As soon as the engine rolled up, the level began to drop, and when the seatbelt sign came off at 28,000 feet, it leveled off at about 1,200.

Looking at the monitor, the flight attendants (one masked and the other unmasked) distributed cookies and stayed at that level until landing, so the level returned to 1,550. After getting off the plane at Burlington, the terminal’s CO2 level was about 1,000 and I finally removed it with a mask.

risk assessment

The CO2 at the airport I returned to Japan on Monday was about 400ppm, which was the same level as outside. Burlington Airport was much smaller than Denver, and few people, including myself, wore masks. When the boarding gate closed, CO2 levels on the return trip reached about 1,000 ppm, dropped to about 850 at takeoff, and stayed there until landing in Denver.

When I took the train back from the concourse to the terminal, my CO2 level reached 650, which was significantly lower than my outbound ride. Given these low levels, I was relieved that leaving the mask off was a safe bet.

Jimenez said my actions follow what is called a “risk budget.” I used the data to tune the response. Jimenez said he still wears a Particulate Respirator on the plane and tries to eat in advance for short flights, otherwise he must remove it when eating on board. rice field. He said carrying a CO2 detector allowed him to make informed decisions about possible exposure to COVID.

“We are all forced to do so,” he said of his constant decision on risk. “We don’t want to live like monks.”

For me, the detector is a simple form of reassurance about my relative risk. You will be prompted to wear a mask in indoor areas with high CO2 levels, but you can skip in areas with low levels.

As my parents say, in the future, the evidence is in pudding. And in this case, that means yet another negative COVID-19 test result when I return to Denver.

This article was originally published in USA TODAY: Airplane COVID: What I learned by measuring CO2 levels in flight