I grew up in a time before widespread central air conditioning
and during a time when windows opened and buildings leaked like sieves. In
recent decades building maintenance have perfected sealing leaks and minimizing
number of air changes per hour. First there was sick building syndrome, then SARS-CoV-2,
the virus that causes COVID-19 arrived and we remembered why we might want
fresh air. Ensuring proper ventilation
with outside air can help reduce indoor airborne contaminants, including COVID-19,
and other viruses. Also, HEPA air filters are good for removing wildfire
smoke and we should consider investing in one for our homes.
In a study recently reported at the World
Health Organization Europe Indoor Air Conference, researcher Catherine
Noakes reported on the University of Leeds study where thirty primary schools
were assigned to three groups balanced for school type (building; ethnicity;
free school meals; total student numbers). These were randomly allocated to
three groups: control; HEPA-Air Cleaning Technologies; UVC-Air Cleaning Technologies. All schools were predominantly
naturally ventilated and relied on manual opening of windows and doors to
ventilate classrooms. All classrooms were equipped with air quality
monitors.
The researchers found that air quality data indicated
comparable ventilation rates between groups, and a 48% mean reduction in
particulate matter in the HEPA classrooms which were equipped with a free
standing HEPA blow filter about the size of
20 gallon kitchen trash can. The HEPA filter in classrooms was found to reduced
the number of covid-19-related sick days by more than 20%.
Only absences related to covid were tracked, but the researchers
also believe that the HEPA filters probably also cut other respiratory illnesses
like colds and flu. Air filters can cost several hundred dollars and can be
noisy, but really produce results. Other studies of the use of HEPA air filters
in a hospital in Cambridge UK is expected in the near future.
No comments:
Post a Comment