This commentary is by Yves Dubief, an associate professor of mechanical engineering, Covid researcher in the area of aerosol dispersion, and parent of two vaccinated grade students. He has no affiliation or support from the UVGI or the CO2 monitoring industry.
The $2 million incentive program for schools that meet vaccination benchmarks, an initiative of Gov. Scott and Secretary of Education Dan French, signals that there is still significant funding available to help schools reduce risks of Covid-19 transmission.
We know how the virus is mostly transmitted, via aerosols, and we have the technology and mitigation strategies to decrease airborne viral load, as shown by the gym example. So why isn’t the administration focused on implementing these solutions to reduce risks?
Most schools in Vermont have implemented robust Covid protocols based on universal masking, and improved air quality control in classrooms. The robustness of these protocols is, however, threatened by the lunchroom situation, especially as we are heading into weather that will make outdoor lunch impossible. Children are unmasked, and talking loudly, the worst-case scenario of aerosol generation with the more infectious Delta variant.
The $2 million incentive program is said to be funded out of the one-time Biden federal aid for Covid. The priority for any unused such funds should be for solutions designed to make a lasting impact on schools’ indoor air quality control, specifically in cafeterias.
The $2 million would buy 800 upper room UVGI (ultraviolet germicidal irradiation) systems with a coverage of 1,000 square feet per unit, or a total coverage of 800,000 square feet. Upper room UVGI are highly recommended by the CDC for school cafeterias in particular. They are safe and proven systems designed to achieve a much higher air change per hour than air purifiers (30 ACH vs. 6 for good air purifiers/ventilation systems).
Because UV irradiation kills viruses and bacteria, upper room UVGI systems also reduce the incidence of common cold and flu. The benefits of this investment will far outlive the pandemic.
Assuming that there is more than $2 million left of federal funds, portable carbon-dioxide sensors are effective indicators of both indoor air quality and risks of airborne transmission in the classroom. The outside concentration of C02 is 400ppm. EPA defines excellent indoor air quality as the C02 concentration below 600 ppm, good under 800 ppm, fair under 1000ppm. Concentrations above 1,500ppm have negative (but fully reversible for reasonable concentrations) impacts on cognitivity: drowsiness, sleepiness. Measurements of C02 in K-12 classrooms have shown instances of concentration as high as 4,000ppm! From the perspective of Covid, the higher the concentration, the longer the aerosols stay in the room and the higher the risk of infection.
From the learning perspective, how could we expect students to retain information, engage in critical thinking, and simply not fall asleep in a room with high C02 concentration? A C02 sensor is a tool for teachers to plan outside breaks, allowing natural ventilation of the room, to avoid giving an exam when C02 concentration is too high. It is a tool for schools to identify poorly ventilated spaces and request funds for improvement.
Gov. Phil Scott and Secretary of Education Dan French should show a real commitment to the children of Vermont by using available resources to implement science-based solutions to control indoor air quality and by investing in long term solutions that benefit also schools, not just the schools from the community with higher vaccination rate that also happened to be located in the wealthiest communities.
Our children made significant sacrifices to keep elderly safe. We have the tools to keep them safe and the Scott administration needs to bring these tools in schools now.
