Dr. Paula Olsiewski and Dr. Gigi Gronvall
The CDC has strongly advised everyone to stay home this Thanksgiving. By celebrating only with the people you live with, you can limit the spread of SARS-CoV-2 which is accelerating around the country at the fastest rate yet, and protect yourself, your family and those living in your community.
However, it’s clear, as we saw images of packed airports this past weekend, that many people will disregard this guidance and gather this Thursday or the days that follow with extended family and friends. For these get-togethers, there are ways to lower the risk.
Getting tested for the virus is a good idea, but tests are only a snapshot in time — and as the White House Rose Garden outbreak demonstrated, they can’t be the only tool used to reduce the spread of disease. There are now hours-long lines to get a COVID-19 test, and wait times for results have increased to 4 or 5 days. In recent months, it’s become even more clear how important improving indoor air quality is to limiting the spread.
How the virus can spread and steps to prevent it
The virus is spread not only by sick people but by apparently healthy but infected people, who shed virus into the air with every breath. The higher the local infection rate, the higher the number of people shedding virus in your community. You can estimate the risk of attending an event based on local prevalence. While most transmission of the coronavirus is thought to be through close contact, scientists now believe that virus particles can linger in the air, travel more than six feet, and that indoor environments with poor ventilation can be especially risky. There is a large and growing body of research evaluating this critical risk, along with corresponding EPA guidance, and while much more needs to be learned, it is time every person improves the air quality inside their own home.
Here’s what you need to do:
1. Wear masks always. If someone is in your home who does not live there, everyone should wear masks. Keep indoor exposures short.
2. Add a filter. If your home has mechanical ventilation (a central heating and air conditioning system that moves air through ducts), install a higher efficiency filter (MERV 13 if possible).
3. Turn the fan on. Set the fan in your home to “on” instead of “auto” so that air is constantly being filtered.
4. Open the windows. If your home has natural ventilation (windows that open, room air conditioners, and radiators for heating) open the windows to increase ventilation. Be sure that you can feel a cross breeze, so you know that fresh air is being introduced to your home.
5. Add a portable HEPA air cleaner. Use a portable HEPA air cleaner that matches the size of the room and run it continuously. This is especially important when people who do not live in your home are visiting, even briefly. Here’s a DIY hack using a box fan and a MERV 13+ filter.
2020 Thanksgiving:Cook your turkey, but cancel your traditional Thanksgiving plans
6. Test air circulation using a carbon dioxide (CO2) sensor. Outdoor air levels of CO2 hover around 400 parts per million. Indoor readings higher than 800 parts per million indicate that your ventilation is not optimal and it’s time to increase ventilation (this is different from the carbon monoxide detector you should already have in your home).
Taking these steps will help now and in the future
Taking these steps to improve air quality in your home should help in the months ahead to limit risks of transmission of COVID-19. Implementing what we know about improving air quality will help to make other indoor spaces — schools, restaurants, airports — safer as well, before most people can be vaccinated against this virus.
Saving lives this Thanksgiving:Thanksgiving 2020 will be different. It’s a time to save lives and celebrate resilience.
All this being said, the safest course of action for this Thanksgiving is to stay home, limit contacts, and do your part to change the trends in community spread of COVID-19 disease. When community spread of COVID-19 is low, we all benefit.
Dr. Paula Olsiewski is a contributing scholar at the Johns Hopkins Center for Health Security. She is a pioneering leader in policy and scientific research programs in the microbiology and chemistry of indoor environments. Dr. Gigi Gronvall is a senior scholar at the Johns Hopkins Center for Health Security and an Associate Professor at the Bloomberg School of Public Health. She is an immunologist by training.