The COVID-19 pandemic isn’t going away any time soon, and as people begin to move indoors for the fall and winter seasons, it’s clear we need to do everything we can to protect ourselves, our families, and our communities. Air filtration will play a key role in the coming months as Canadians move inside, which means it may be time to invest in an air purifier for COVID prevention.
Over a grueling first wave and long summer, experts have learned a lot about the transmission of SARS-CoV-2 (the virus that causes COVID-19.) We know that spending time with people inside is riskier than meeting outside since it’s difficult to maintain a safe distance of 6-feet. Now, thanks to updated recommendations from the World Health Organization, along with the US, Canada, and many other countries, we also know that the coronavirus can spread through aerosol transmission.
So, are air purifiers effective for COVID-19 prevention, and what do you need to look for?
How Does COVID-19 Spread?
New research and recent case studies have shed light on how the coronavirus spreads indoors. Interactive mapping illustrates how dangerous indoor environments are without natural or mechanical airflow.
Case studies consistently show that masks are not enough to prevent coronavirus transmission when people spend a prolonged amount of time together indoors. Masks reduce your risk, but they need to be combined with sufficient ventilation.
It’s estimated that if an infected person and five other people spend four hours speaking loudly in a room together, all five of the other people will become infected, even if they were seated apart. If every person were wearing a mask under the same circumstances, four people are still likely to become infected. If the entire group continues to wear a mask but also cuts the visit in half and adds natural or mechanical ventilation, only one person is likely to become infected.
These scenarios play out time and time again in homes, offices, churches, schools, bars, and restaurants where people gather inside. It’s becoming more and more clear just how important airflow and proper ventilation are to combating the spread of COVID-19.
Person-to-Person Transmission
At this stage, health experts believe a key factor in the spread of COVID-19 is through person-to-person transmission. This refers to people who are in close proximity to one another—within six feet. If one of these people is infected with COVID-19 and they cough, sneeze, speak, or sing, respiratory droplets are produced that can be inhaled by or land in the mouths and noses of those around them.
The CDC says, “the more closely a person interacts with others and the longer that interaction, the higher the risk of COVID-19 spread.”
It’s also extremely important to remember that COVID-19 can be spread by people who are not showing any symptoms—which means that simply sharing the airspace of someone unknowingly infected with COVID could result in you becoming infected yourself.
Airborne Spread
In May of 2020, a nursing home outbreak in Montreal infected 226 residents and 148 employees. Virus particles were found in the air at the home, and it’s possible a faulty ventilation system contributed to the outbreak.
We know the virus can remain in the air for a long time depending on indoor conditions. In July, The New York Times shared that “the coronavirus can stay aloft for hours in tiny droplets in stagnant air, infecting people as they inhale.” Not only can COVID-19 survive for hours in the air, but depending on a room’s airflow, temperature, and humidity, a cough can send respiratory droplets as far as 19 feet away, and a sneeze can send droplets up to 26 feet.
Canada updated its COVID-19 guidelines to include the risk of airborne spread. The guidelines now say, “SARS-CoV-2, the virus that causes COVID-19, spreads from an infected person to others through respiratory droplets and aerosols created when an infected person coughs, sneezes, sings, shouts, or talks.” The new guidelines recommend additional measures be taken in high-risk areas such as closed spaces, crowded places, and settings where close-range conversations, singing, shouting, or heavy breathing occurs. They emphasize the importance of ventilation systems as well as the need to draw as much fresh air as possible from outside to prevent transmission indoors.
The CDC also updated its recommendations to include airborne transmission of SARS-CoV-2. They say, “Some infections can be spread by exposure to virus in small droplets and particles that can linger in the air for minutes to hours. These viruses may be able to infect people who are further than 6 feet away from the person who is infected or after that person has left the space.”
Surface Transmission
Surface transmission is no longer thought to be a major factor in the spread of COVID-19. In May 2020, the CDC updated its guidelines concerning the surface transmission of COVID. They stress that while it is possible that a person can become infected by touching a surface contaminated with COVID-19, it’s not “the main way the virus spreads.”
Are Air Purifiers Effective For COVID-19 Prevention?
Air Purifiers Reduce Viral Load
Just because you are exposed to COVID-19 doesn’t mean you’re going to become infected. Transmission depends on a number of factors, including the health of your immune system and how much of the virus you come into contact with. Viral load refers to the quantity of the virus in the air. Air purifiers constantly filter the air in your indoor space, removing virus particles so that if you do become exposed to the virus, you’re less likely to get sick because the viral load isn’t high enough to infect you.
Air Purifiers Reduce Air Pollution
There’s a clear connection between air pollution and coronavirus infections. A 2020 study concluded that “The highest number of COVID-19 cases were recorded in the most polluted regions with patients with more severe forms of the disease requiring ICU admission. In these regions, mortality was two-fold higher than the other regions.”
Poor air quality can make you more susceptible to catching the virus, and it could mean more severe consequences. While you can’t control the air outdoors in the city you live in, you can control the quality of air in your home and workspace. Air purifiers remove harmful air contaminants, including benzene, formaldehyde, dust, dirt, and smoke.
Air Purifiers Protect Your Immune System
If you do come into contact with COVID-19, you want to give your body every chance possible of fighting off the virus. Building and maintaining a strong immune system does just that. In addition to making healthy lifestyle choices, an air purifier protects your immune system by filtering out harmful bacteria, pollution, and chemicals.
Whether at home or the office, we are regularly exposed to volatile organic compounds (VOCs), which include a wide variety of chemicals found in paint, printers, cosmetics, some air fresheners, and many other household products. Quality air filters scrub the air, removing these chemicals so they can’t interfere with your immune health.
Choosing an Air Purifier For COVID-19 Prevention
Super HEPA Filter (0.1 Micron)
In order to properly filter airborne viruses and bacteria, such as the coronavirus, an air purifier needs to be able to filter smaller micron particles and microorganisms from the air. The size of the coronavirus is approximately 0.125 micron in diameter. A Super HEPA filter removes 99.9% of all particles at 0.1 micron in size, whereas a regular HEPA removes 99.97% of all particles at 0.3 micron.
Look for air purifiers with Super HEPA in order to filter viruses and bacteria smaller than 0.3 micron.
Activated Carbon Filter
Activated carbon filters are small pieces of carbon that have been treated to be very porous.
They’re designed to remove harmful chemicals, such as formaldehyde and benzene, from the air. HEPA filters and activated carbon filters need to work together. Only having a HEPA filter will mean chemicals that stress your immune system can pass right through.
Germicidal UV
A Germicidal UV Bulb is an electric light that produces ultraviolet C (UV-C) light. The short-wave ultraviolet light is proficient at neutralizing airborne germs, larger viruses, and mold spores by disabling their DNA. The most effective air purifiers have this technology working alongside a Super HEPA filter and activated carbon filter.