COVID-19, Wildfires, and Indoor Air Quality
Communities affected by wildfire smoke may choose to set up or identify cleaner air spaces and cleaner air shelters where people can seek relief from wildfire smoke. Public health guidance for sheltering from wildfires in cleaner air spaces or cleaner air shelters should be adapted to accommodate safety measures related to COVID-19.
CDC's Interim Guidance for General Population Disaster Shelters During the COVID-19 Pandemic may be useful to communities setting up cleaner air spaces or shelters. Communities should note that the requirements of state, local and tribal agencies supersede these recommendations.
Specific information about how to set up cleaner air spaces and shelters is available in Wildfire Smoke: A Guide for Public Health Officials in Appendix B.
In addition, ASHRAE (formerly the American Society of Heating, Refrigerating and Air-Conditioning Engineers) offers a Planning Framework for Protecting Commercial Building Occupants from Smoke During Wildfire Events (PDF) that recommends HVAC and building measures to minimize occupant exposures and health impacts from smoke during wildfire and prescribed burn smoke events, including some considerations for reducing transmission of SARS-CoV-2.
When setting up and operating buildings as cleaner air spaces or shelters, it is important to note that recommendations regarding ventilation with outdoor air are typically different for reducing exposure to wildfire smoke and reducing the transmission of SARS-CoV-2. For wildfire smoke, ventilation is generally minimized to reduce smoke entry into the building, while, for SARS-CoV-2, ventilation is generally increased to reduce the concentration of airborne contaminants, including viruses, indoors. Increasing indoor air filtration may help to reduce the concentration of both smoke particles and SARS-CoV-2 when additional ventilation with outdoor air is not possible. See Air Cleaners, HVAC Filters, and Coronavirus (COVID-19) for more information.
Cleaner air shelter managers will need to balance the potential tradeoff between exposures to wildfire smoke and SARS-CoV-2 by monitoring indoor and outdoor condition and adjusting ventilation and filtration approaches as appropriate.
Create a Clean Room to Protect Indoor Air Quality During a Wildfire
In some cases, the combination of COVID-19 epidemic and wildfires may require modifying emergency plans. If there is an active fire in your area, local authorities may advise you to stay indoors or create a clean room rather than evacuate. Setting up a clean room at home can help reduce your exposure to dangerous or unhealthy wildfire smoke while indoors. Everyone can benefit from spending time in a clean room during a wildfire, but it may be most helpful for sensitive individuals like the very young, very old, and people with heart or lung problems. To create a clean room (e.g. a bedroom with attached bathroom), keep doors and windows closed, run your air conditioner or fans to stay cool, filter the air with a portable air cleaner, and avoid activities that produce particles (e.g. smoking, burning candles or incense, cooking). Spend as much time as possible in the clean room.