Riverside students spend 35 hours or more a week on campus. Teachers spend forty-plus. Yet most don’t think about how much the air they breathe affects the work they do.
Data gathered by an air quality monitor during the fall semester on Riverside’s campus suggests that some classrooms have high carbon dioxide levels that could affect learning and overall health.
“I had no idea it was even a problem,” said American History teacher Anna Allman.
CO2 levels in Allman’s trailer are about 3500 when students are in class. That’s too high for students to function at their highest level, according to the CDC.
Carbon dioxide is not a toxic gas. It is a natural part of the atmosphere, but too much of it displaces the oxygen in an area. CO2 levels increase as people in a room exhale, and the school’s ventilation systems can’t remove it fast enough. So in a room with too much carbon dioxide, less oxygen will go to the brain, causing a decrease in productivity, drowsiness, and even headaches.
Good quality air contains between 400 and 1000 parts per million (ppm) of CO2. Outdoors, the air is about 500ppm.
The CDC estimates around 14 million school days are missed each year due to poor air quality. CO2 levels between 1,000 and 2,000 ppm are associated with drowsiness, loss of concentration, and fatigue.
A Harvard study in 2016 found a 15 percent decrease in cognitive function at 950 ppm, and a 50 percent decrease at 1400 ppm. Levels between 2,000 and 5,000 are associated with headaches and nausea. Although more research may be needed to confirm these findings, it shows how high CO2 levels can impact student learning and general wellness.
Indoor CO2 levels depend on three main things: size of the space, how many people there are, and the room’s ventilation. This means places like the hallways or cafeteria have better air quality than places like the stairways or classrooms, and worst of all is the trailers. Levels of about 700 ppm were recorded in the front lobby, and about 800 ppm in the cafeteria. In smaller rooms, like stairways, it was around 1200 ppm.
At the beginning of a class period, the CO2 levels in classrooms are about 1000 ppm, but as the period goes on, it goes up to 1500 because of a lack of ventilation. Teachers who leave their doors and windows open in their classrooms recorded levels of about 1200 ppm. Levels also go up as the day goes on, causing students to feel even more tired during third and fourth period.
The trailers can have some of the worst levels in the school because of the smaller, more crowded space, and older ventilation systems. Riverside was originally designed to have three floors, but a lack of funding led to only two floors and trailers outside, so the trailers are on a separate air system from the rest of the school, according to Environmental Science teacher Shaun Thompson.
“The trailers are awful,” said Thompson.
There are, however, simple ways to decrease CO2 levels. In trailers with windows open, levels were recorded to lower to about 2500 ppm. And in trailers with doors open, the air in the trailer is about the same as outdoor air. When it’s too cold to leave the doors open, letting students go outside for just a few minutes will give them fresh air. Indoor classrooms can have their doors open all the time.
Another good solution is putting plants in classrooms, which can lower CO2 levels by about 10 percent. Plants also have other positive effects, such as reduced stress, increased creativity and improved concentration and memory, according to the organization A Plant in Every Classroom. A study by The Royal College of Agriculture in England also showed that a plant in the room can improve attention by up to 70 percent.
High levels of CO2 can impact attendance, too. Every 100ppm increase in CO2 beyond 1000 has been associated with a half day of school missed.
“One out of three people will get sick at the workplace, and carbon dioxide could be one thing that could contribute to it, which is unfortunate,” said Thompson.
According to a study in Scotland, if the CO2 levels in most classes are around 1400 ppm, this could cause students to miss about two days of school per year.
Students with asthma can experience worse symptoms from carbon dioxide. One in thirteen school-age children have asthma, according to the US Environmental Protection Agency, and asthma-related sickness is the leading cause of school absence due to illness in the United States.
High CO2 levels can also indicate an indoor environment conducive to the spread of airborne viruses like COVID. Individuals infected with the coronavirus breathe out the virus with their CO2, so if the CO2 levels are high and ventilation is not taking it out of the room COVID, along with any other airborne viruses present, could linger in the air.
In addition to improving student and teachers’ health, improving ventilation could also save the school money in the long-term.
Levels of CO2 in Earth’s atmosphere reached 419 ppm in May, a 12-percent increase since 2000 and higher than it has been in over 4,000,000 years. Every year, humans add about 40 billion tons of CO2 to the atmosphere, according to the National Oceanic and Atmospheric Administration.
“Each year we put more carbon dioxide into the atmosphere than natural processes can remove,” says the NOAA in 2020.
Climate activists often link this data to global warming and stress the importance of reducing CO2 emissions as quickly as possible.
Schools consume about seven percent of the energy of all commercial buildings in the USA. Riverside can lower its carbon emissions by reducing energy usage. This can be done by turning off lights, or installing motion sensors so lights are only on when they need to be, and recycling as many materials as possible.