REDUCING CO2 LEVEL. Healthcare experts discuss how improving ventilation and reducing CO2 emissions can lower the risk of Covid-19 transmission indoors. The Zoom meeting of healthcare professionals and various sectors was organized by the Office of the Presidential Assistant for the Visayas and the Inter-Agency Task Force for the Management of Emerging Infectious Diseases. (Video grab from OPAV)
CEBU CITY – Healthcare professionals in Cebu are working with the government in ensuring that indoor settings will become safe by reducing virus transmission of coronavirus disease 2019 (Covid-19).
In a statement on Tuesday, the Office of the Presidential Assistant for the Visayas said it collaborated with the Inter-Agency Task Force for the Management of Emerging Infectious Diseases (IATF-EID) in tapping experts to improve ventilation and limiting carbon dioxide (CO2) emissions, apart from limiting the capacity, as new normal in indoor events.
It said OPAV and IATF officials organized meetings with various sectors to identify measures that could help in the safe reopening of the Cebu economy, considering that most business establishments have an indoor setup.
Dr. Antonio Dans, convenor of the Healthcare Professionals Alliance Against Covid-19 (HPAAC), said in a Zoom meeting on Monday Covid-19 transmission can be mitigated by reducing CO2 emissions in indoor settings through proper ventilation.
During the virtual conference, he said a 400-parts-per-million (ppm) CO2 emission is considered safe while 400 ppm to 500 ppm is acceptable but an 800 ppm CO2 emission is risky, while 4,400 ppm is a dangerous level.
He noted that the efficacy of wearing a mask diminishes in an indoor setting with higher CO2 concentration, which requires improved ventilation to reduce particle emissions.
“The higher the CO2 level, the more the air you’re breathing comes from other people,” he pointed out, adding that a person could inhale and exhale 10 liters of air per minute.
Meanwhile, Dr. Leonila Dans, Dans’ wife who is an epidemiologist and co-convenor of HPAAC, stressed the importance of having good ventilation in combination with wearing of face masks, physical distancing and limited time of exposure as a way to reduce coronavirus transmission.
Both doctors said indoor ventilation can be improved through exchanging indoor air with the air coming from outside, which is the inexpensive way of reducing CO2.
This can be done by keeping the windows open and through the use of exhaust fans, the experts said.
For windowless venues, high efficiency particulate air (HEPA) filter devices are advisable as these can trap droplets of respiratory infections (or other particles) which may carry viruses and prevent them from remaining indoors.
The doctors said measuring air quality could be helpful in coming up with measures to reduce transmission.
“We should start monitoring air quality if you want to make sure that schools and workplaces are safe,” Leonila said.
Their advocacy for safe venues came after President Rodrigo Duterte on Monday approved the holding of pilot in-school classes in areas with minimal risk for Covid-19 transmission.
The OPAV statement said proper ventilation would help pilot schools in Central Visayas reduce infection risks.
It quoted a research article from the Cooperative Institute for Research in Environmental Sciences (CIRES) and the University of Colorado Boulder published in Science Daily on April 7 which noted that “tracking CO2 levels indoors is an inexpensive and powerful way to monitor the risk of people getting Covid-19”.
The research was based on the fact that CO2 can serve as a "proxy" for a number of viruses in the air.
Edmun Liu, head convenor of Project Balik Buhay, suggested that guidelines focus only on air quality standards requirement and allow businesses to determine how to achieve the set standard.
Meanwhile, Department of Health (DOH)-Region 7 chief pathologist Dr. Mary Jean Loreche suggested that the approach to a safe reopening of the economy include the small businesses such as the "carenderias" or eateries, barber shops and beauty salons.
The meeting participants also included IATF-Visayas chief implementer Melquiades Feliciano, infectious disease specialist Dr. Brian Lim, Dr. Helen Madamba of the Vicente Sotto Memorial Medical Center and other Cebu-based physicians. (PNA)
