We have all had to learn new things — social distancing, face covering protocols, staying at home — during this pandemic and the research and health community is no exception. In fact, they are continually discovering novel things about COVID and how to protect public health.

Transmission of the COVID virus is thought to be mainly from person-to-person contact through respiratory droplets from coughing, sneezing, and talking which enter the lungs. The six-foot social distancing that we are all familiar with has been a mainstay precautionary practice to reduce the spread of the virus. However, new research shows that the six-foot distance may actually not be adequate to prevent exposure in indoor settings.

Numerous studies show that microdroplets (essentially aerosols) can stay suspended in the air much longer than previously thought, travel more than six feet, and circulate in rooms. The new research suggests that wearing facemasks in public buildings, offices, etc. maybe a prudent precaution. Further, heating, ventilation and air conditioning (HVAC) systems can move and recirculate these microdroplets (~ 1 micron in size), and therefore filtration is recommended. Filtration will not eliminate all risk of transmission of airborne particulates, since several other factors influence disease transmission, but is one tool in addition to facemasks and handwashing to reduce risk.

CDC, EPA and ASHRAE provides some practical guidelines to management of indoor air quality: 

• Using a minimum of a 13 Minimum Efficiency Reporting Value (MERV) HVAC filter. This level can capture up to 85% of particles 1-3 microns in size. These filters are the pleated kind and can be purchased online or at some hardware/box stores, (though often they only sell MERV 12 or lower). Note: These filters reduce air flow slightly and must be replaced every three months to make sure they don’t get clogged to where air flow is restricted possibly damaging the system
• Maintain the fan component of the HVAC system to run 24/7. Most thermostats allow for that option. Simply turn the fan from auto to on
• If weather and temperature conditions permit consider increasing fresh airflow from outside
• Consider using a portable room air cleaner a high-efficiency particulate air (HEPA) room filter or. This may be especially a wise practice if someone has been sick. A HEPA filter (equivalent to > MERV 16) will provide up to 99% capture of the virus droplets.

Being safe during this pandemic has adjusted our lifestyle and practices, and we need to remain diligent and adaptable to minimize risks. Indoor air quality is yet another important consideration to protect your health.