CO2 monitors could help prevent the spread of COVID-19, experts say

As the number of new COVID-19 cases in the US continues to decline, health experts are promoting the use of CO2 monitors as a way to drive the trend in the right direction as the country begins to lift restrictions on social distance.

“The use of CO2 monitors is, in my opinion, a very important part of the process of reopening restaurants and schools and businesses, because it is a relatively inexpensive, easy-to-use measure of how well the ventilation rate matches the number of people in the room, “Alex Huffman said. , an associate professor of chemistry and biochemistry at the University of Denver, told Yahoo News.

The Centers for Disease Control and Prevention has been warning Americans for months that COVID-19 is being spread by respiratory drops, such as when someone coughs, sneezes or even just breathes.

“These viruses can infect people who are infected beyond 6 meters of the person being infected, or after the person leaves the space,” the CDC says on its website.

Huffman is among a group of experts currently studying how the CO2 we exhale can serve as a proxy to determine how much potentially infectious aerosol is in the room. CO2 monitors, in turn, can be used to determine the risk of transmission in a given environment, Huffman said, including situations in which people do not wear masks or do it incorrectly. As a general rule of thumb, as CO2 levels rise, the risk of contracting COVID-19 increases.

“Over time, it builds up, no matter how far you are. “There is no safe distance to inhale it,” said Huffman.

In an interview with Yahoo News, Huffman explained how CO2 monitors work and why they can help the country maintain COVID-19.

How will monitoring CO2 levels help stop the spread of COVID?

“When you breathe, you exhale CO2, as well as aerosols that come out of your mouth,” Huffman said. ‘We can not measure the respiratory infectious aerosols in the room very easily. We can measure CO2 very easily and relatively cheaply, so we use it as a proxy. As CO2 builds up, so does the contagious aerosol risk. ‘

The story continues

Regarding the reopening of restaurants, schools and businesses, Huffman said the mitigating measures to place CO2 monitors around those businesses “are not difficult.” Once the CO2 monitors (which cost an average of $ 200) are in place, “you have a process where you observe the numbers and then make decisions and say, ‘If the number is too high, we change our protocols'” he said. said.

Once CO2 monitors are in place, what is the ideal range?

An average CO2 reading in the open air is about 400 parts per million. Indoors, Huffman said you want to keep the CO2 reading as low as possible, and there is no perfect cut-off point. But he said anything less than about 800 parts per million is good. Anything above 800 parts per million means that aerosol builds up, which increases the risk of COVID infection.

What can you do to increase ventilation and reduce CO2 concentration?

Increasing ventilation is key, Huffman said. This can be done just like opening a window. Cracking a window in a car, for example, can make a big difference. Huffman recently rode with four other family members, and CO2 levels started at about 400 parts per million. After about an hour in the car with the windows up, the CO2 concentration skyrocketed to 4,000 parts per million. Huffman opened the windows and levels dropped to about 600 parts per million.

Huffman said that if you are in your home, you can also turn on exhaust fans, such as in the bathroom or kitchen, that draw air out of the home. He added that although it is not the same as ventilation, you can clean the air in your home. “So you can have a room-portable HEPA filter, or you can draw air through the ventilation system in your home, as long as you have a good MERV 13 filter,” he said. “It’s not going to touch the CO2 in the room at all, but it will clean the aerosol that is in the room.”

(Huffman also offers some do-it-yourself ways to measure ventilation in your home here.)

What other steps help reduce COVID-19 distribution?

Huffman stressed that while ventilation and room filtration are certainly important pieces of the puzzle to reducing the risk of COVID-19 spreading in any environment, it is also important to continue these other mitigation efforts. ‘Masking is still critical. Distance away from [people not in your household] is critical. And it is also critical to reduce the time you spend in that place, ”he said. “These three things are going to be critical, no matter what.”

Read more from Yahoo News: