Wellness Design Strategies For Addressing Wildfire Smoke And Ash In Your Homes During Covid Pandemic

Western states are not new to wildfires or their devastating impacts on area residents. What is new this season is that they’re occurring during a pandemic, exacerbating susceptibility to Covid impacts, especially among vulnerable populations. 

Smoke and ash are darkening the skies outside Stephanie Christenson, MD’s hospital windows into a dystopian haze and inflicting unhealthy air quality index ratings across her region. Christenson is a pulmonologist and assistant professor of medicine at the University of California, San Francisco. How much permanent health damage wildfire smoke and ash will inflict on local residents is still unknown, but the lung specialist has concerns, especially for small children, infants, pregnant women, immunocompromised individuals and people with underlying lung or heart conditions.

Vulnerable Groups’ Increased Risk

“Children breathe more air for their body weight than adults, meaning that the overall exposure to their body will be higher. With air pollution in general, it has been shown that increased exposure as a child leads to impaired lung growth, as well as increased risk for asthma.”

Those with immune system deficiencies and heart and lung conditions are already more vulnerable to Covid infection, hospitalization and morbidity.“There is certainly reason to think that air pollution in general, and wildfires specifically, could increase risk of worse Covid-19 symptoms and outcomes. The inflammation from the virus and inflammation from Covid-19 could compound each other leading to worse problems.”

The pulmonologist also observes that both wildfires and Covid lead to increases in hospitalizations for bad respiratory infections, potentially making two bad short term situations worse. On a long term basis, she says, “We have pretty good evidence that exposure to air pollution [and] high levels of particulate matter is associated with increased risk of developing asthma, COPD, heart disease and cancers (lung colorectal, bladder).”

Wellness Design Strategies

So what can someone living near one of these wildfires do? Christenson suggests, “Keep the windows closed and buy an air purifier.” Adding air purification capability to one’s HVAC system is best, she advises, as long as it doesn’t generate ozone, another health risk. “Otherwise portable air purifiers are a good option.”

“I live in the greater San Francisco Bay Area and currently the outdoor air is ‘very unhealthy,’” observes  Max Sherman, leader of ASHRAE’s Epidemic Task Force Residential Team. “We are staying inside and putting our filters to work.  They have served us well over several wildfire seasons. This year we had added some portable air cleaners to the mix for their UV-C disinfection bonus,” he shares. ASHRAE is the professional association that represents heating, refrigeration and air conditioning engineers in the United States.

“The most effective thing people can do to protect themselves — assuming they are not being threatened by the fires directly — is to filter the air they breathe to remove as much of those particles as they can. If you have a forced-air heating or cooling system, or a supply air intake, there is likely a place to put a particle filter.  Filters are rated for performance by ASHRAE Standard 52.2 using a scale called MERV, [Minimum Efficiency Reporting Values].  To get good removal of the particles, you want to have a filter rated at MERV 13 or better on that scale.”

Many older homes are “very leaky,” Sherman observes. “Not only does let smoke seep in, but it is bad for energy efficiency.”  The building scientist recommends having your residence optimized by a home performance contractor and having a simple mechanical ventilation system installed. “This will assure proper ventilation year-round, at minimum energy cost, and also provide better control during events such as wildfires (or pandemics).”

In the meantime, when you might prefer not to have non-household members visit because of the pandemic, adding a filtering appliance to your home or apartment can be extremely helpful, especially if you can move it easily between work from home and sleeping areas. “Portable air filters are usually rated in Clean Air Delivery Rate (CADR), which is a measure of how much filtered air they deliver. A higher value means more particles removed and is better. As I say this, I have one such filter running in my home office, here in smoky California.” There’s a related benefit, he points out: “A good filtration system will reduce risk from both wildfires and Covid-19.”

Sherman adds, “Many of the portable air cleaners have UV disinfection inside them. UV Germicidal Irradiation (UVGI) is a proven disinfection technique. It deactivates viruses, including SARS viruses, quite effectively. The State of California maintains a list of equipment that they have determined is safe and effective,” he shares. As UCSF’s Christenson agrees, in this unregulated category, avoiding problematic appliances can be crucial to your family’s health and safety.

Wildfire Smoke and Ash Tips

The Environmental Protection Agency is another resource Sherman suggests for guidance on wildfire smoke issues and on residential air cleaners. Here are some of the agency’s quick tips for dealing with smoke and ash in your homes and on your property:

• Keep windows and doors closed.
• Use fans and air conditioning to stay cool. If you cannot stay cool, seek shelter elsewhere.
• If you have a central HVAC system, find out if it has a fresh air intake. If it does, find out how to close it or turn the system to recirculate mode.
• Make sure the HVAC filter is in good condition, fits snugly in the filter slot, and is replaced as recommended by the manufacturer. Consider upgrading to a MERV 13 or higher rated filter if your system can accommodate it.
• If you have an HVAC system with a high-efficiency filter installed, run the system’s fan as often as possible to remove particles while the air quality is poor.
• If you have a window air conditioner, find out how to close the outdoor air damper. If you cannot close the damper, consider preparing other cooling options like a fan. Make sure that the seal between the air conditioner and the window is as tight as possible.
• If you have a portable air conditioner with a single hose, typically vented out of a window, do not use it in smoky conditions. Consider other cooling options like a fan or window air conditioner. If you have a portable air conditioner with two hoses, make sure that the seal between the window vent kit and the window is as tight as possible.
• Use a portable air cleaner or high-efficiency filter to remove fine particles from the air.
• If you use a portable air cleaner, run it as often as possible on the highest fan speed.
• Avoid activities that create more fine particles indoors, including: Smoking cigarettes; using gas, propane or wood-burning stoves and furnaces; spraying aerosol products; frying or broiling food; burning candles or incense; vacuuming, unless you use a vacuum with a HEPA filter.
• Protect yourself during ash cleanup; children, older adults, and people with heart or lung diseases, such as asthma, should not participate in cleanup work.