Parents and guardians of Baltimore County public school children and other community stakeholders have been raising questions for months about school air filtration systems and air safety interior amid the coronavirus pandemic. A parent, frustrated by the government’s responsiveness, decided to take matters into their own hands.
Although the county school system’s facilities management department said all schools’ systems were inspected to make sure they were up to code, parents like climate scientist Elizabeth Dahl argue that the code used is a “minimum standard” and that ventilation may not be enough to reduce the spread of diseases like COVID-19.
For that reason, Dahl, who holds a doctorate in earth system science from the University of California at Irvine, tested air quality in Baltimore County schools last fall as part of a citizen science project that ultimately yielded results that she found to be concerning.
She then circulated a petition, which garnered more than 300 signatures from BCPS staff, parents and guardians, and other community members, asking the school system to provide portable particulate air filtration units to high efficiency in all classrooms and indoor spaces where children gather.
HEPA filtration units are 99.97% efficient at capturing human-generated virus particles associated with COVID-19, according to the Centers for Disease Control and Prevention.
And while officials said the type of purifiers shipped to schools contain HEPA filters, the purifiers aren’t in every classroom, Dahl observed. Portable HEPA filters, studies show, can filter the air in spaces that have little or no built-in mechanical ventilation.
The petition also suggested that the school system should switch to at least one MERV-13 filter for all HVAC systems. MERV, or Minimum Efficiency Ratio Value, measures the efficiency of an air filter, and MERV-13 filters are recommended by the CDC and the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) , a global trade association, to reduce virus transmission.
BCPS uses the lowest rated MERV-8 filters; however, last year the school system began changing filters five times a year rather than quarterly as was the case previously.
“Ventilation and circulation system inspections have been performed at all schools to verify that ventilation, circulation and filtration are functioning as intended,” Deborah Soper, BCPS facilities administrative assistant, said in an email. in Dahl. “Facilities staff will continue to perform scheduled preventative maintenance on HVAC systems and change filters more frequently.”
“The systems, as designed, are not adequate,” Dahl said in an email to several school officials. “If the filters are below MERV-13, no matter how often you change them, they still can’t filter out virus and bacteria particles, even when they’re new.”
In his petition, Dahl pointed to new initiatives in Howard County, where MERV-13 filters were provided for every classroom, and in Baltimore City, where HVAC system filters were upgraded to MERV- 13 where possible, and where the filters could not be upgraded. , portable filtration units were provided.
Dahl sent the petition to school officials three times and received no response, she said.
“Complete radio silence from all members of the board, superintendent and zone superintendents, and facilities department,” she said in a Feb. 11 email to The Avenue.
That was after several months of pushing the issue, with no meaningful action taken by the school system, Dahl said.
In addition to numerous emails to BCPS, she also submitted a Public Information Act request to the state for records of the facilities department’s work on school air handling. Elementary Villa Cresta and Parkville Middle, particularly between March 2020 and July 2021, to find out if the schools meet the standards set by ASHRAE.
No such record exists, BCPS General Counsel Margaret-Ann Howie said in response to Dahl’s PIA request.
“The Baltimore County government requires that all new buildings and system retrofits meet the 2015 International Mechanical Code (IMC),” Howie said, adding that the school system has a practice of following “each manufacturer’s standards for HVAC systems; not the ASHRAE standard.
Jurisdictions may choose to adopt IMC for HVAC systems, but the code, Dahl noted, predates the pandemic.
Dahl, in a later email, clarified that she was asking for documentation and/or data showing that the standards used are, in fact, being met. Howie, after answering Dahl’s further questions, said any additional requests would cost him dearly, as staff spent “over three and a half hours” processing his request, exceeding the 2 hour time limit allowed by law.
Not feeling like her concerns had been “enough considered”, Dahl developed her own assessment to show why she thought further analysis on the matter was needed.
She collected data at five-minute intervals using standalone Aranet4 monitors to measure carbon dioxide in the air – carbon dioxide, studies show, can serve as a proxy for COVID-19 transmission . For several consecutive days, monitors were placed in classrooms, or students wore them, all for estimated ventilation rates.
The data was collected from eight local schools, including Villa Cresta Elementary and Parkville Middle, the schools attended by Dahl’s two children. She also collected data from two other elementary schools, three other middle schools and one high school.
Dahl found through the Citizen Science Project that Villa Cresta and Fullerton Elementary School appeared to be the best-ventilated schools of those surveyed, while Parkville Middle and Warren Elementary appeared to be among the least ventilated.
A classroom at Villa Cresta, for example, still showed carbon dioxide levels exceeding 800 parts per million, the target benchmark for good ventilation as suggested by the CDC, for 31% of the day. Additionally, a student at Parkville Middle School was exposed to air above the benchmark for 82% of the school day.
At 800 ppm, 1% of the air you breathe has been breathed out by someone else, according to the CDC, and a school-aged child’s respiratory rate is 14 to 24 breaths per minute. As such, a child in a typical 90 minute class period will take between 12 and 22 breaths of air from another person.
Dahl said the data is limited, in part because she had little or no control over the placement of carbon dioxide monitors, or whether windows or doors were opened in student classrooms. .
Still, the data she found was interesting, she said, in that students at Parkville Middle, Parkville High and Pine Grove Middle spent most of their school days in spaces where levels of carbon dioxide exceeded 1000 ppm. Additionally, a classroom at Warren Elementary School showed levels above 1,000 ppm for 92% of the school day.
In order to share information about school air purification and the progress of these efforts, Dahl created the Air Filtration for Baltimore County & Greater Baltimore Area Schools Facebook group.
Mary Taylor, a member of that group and vice chair of the Baltimore County Parent and Student Coalition, joined the campaign, testifying at a recent public hearing on the council’s fiscal year 2023 budget. school on the need for schools to increase filter ratings to MERV-13 or provide portable HEPA air purifiers.
“Many of our schools,” she said, “continue to be poorly ventilated and operate without filtration. This isn’t just a pandemic issue; it’s a matter of fairness and justice for all Baltimore County students who deserve to breathe clean air at school.
She adds that air ventilation rates, even outside of a pandemic, can impact student health and learning outcomes, which research has, in fact, shown.
Some progress in improving air quality in schools could also be seen at the state level this year. The legislation, which would require each county school board to employ a qualified investigator to conduct air quality tests in public schools and then post the results online, will receive a hearing on February 24. Several Baltimore County delegates are co-sponsoring the House version of the bill, and Senator Kathy Klausmeier, representing District 8, is sponsoring the Senate bill.
“BCPS employs a variety of engineers, professionals and staff to ensure BCPS facilities are safe and meet the needs of our students and staff,” a BCPS spokesperson said in an email. mail of February 8 to the Avenue. “In addition, all mechanical systems in our schools must provide sufficient ventilation for maximum space occupancy, and during the pandemic extra efforts have been made to inspect all equipment to ensure proper operation and maintenance. safety, including necessary upgrades and repairs.”