Healthy Home: Clearing the Air

Healthy Home: Clearing the Air

World Changers Logo 1200px v2

Pollution—indoors and out—is a huge problem for homeowners. Here are new ways to combat it.

When smoke fills the air, one of the first things people are told is to stay inside because it’s a health hazard to remain outdoors. That warning has become commonplace over the past few years, when more than 237,000 wildfires resulted in 37.5 million acres burned across the United States from 2020-2023, according to data from the National Interagency Fire Center (NIFC) and the NOAA National Centers for Environmental Information. In addition, nearly 1 in 7 Americans experienced dangerous air quality from wildfires in 2023, according to NPR.


Particulate matter generated by massive wildfires in the Western U.S. made it unsafe to breathe air outside or inside the home. Credit: iStock/JasonDoiy

Those totals appear even more grim when combined with the findings of a report by the University of Washington, which determined that indoor air quality can be four times worse on fire days than non-fire ones.

That, in turn, increases the chance of health hazards ranging from eye irritation, persistent coughing and aggravated asthma, to deadlier events such heart failure, lung disease, and even dementia, according to a study by the University of Michigan. 

Considering that people spend about 87 percent of their time indoors, improving air quality should be a priority, according to Yuming Guo, professor of global environmental health and biostatistics at Monash University in Melbourne, Australia. In recent years the school has conducted several studies of its own regarding global air quality.

According to Guo, the culprits are PM2.5, microscopic particles which at 2.5 micrometers are about 5 percent the width of a human hair. They are capable of bypassing a person’s respiratory system defenses, enter the bloodstream and travel to vital organs. They can also seep through closed doors and shuttered windows and contaminate indoor air.

Simply closing up a house during a smoke-heavy day will reduce indoor PM2.5s by about one-third, according to Allen Goldstein, a professor at the University of California at Berkeley’s Department of Environmental Science, Policy and Management. Moderate efforts such as indoor air filters can cut the number of remaining PM2.5s by 50 percent. More-sophisticated products such as air purifiers, whole-home ventilators and intelligent air monitors help keep indoor air quality (IAQ) far closer to outdoor, non-smoke day levels.

Various outside factors, such as a home’s age, the distance of a wildfire, direction and speed of air current, and even location of filtration systems within a house will impact how effective air purifying efforts are—as is education of the public on how to properly use the devices. “When people have information about the smoke coming their way, they can act to protect themselves and do it effectively,” Goldstein notes.

Charles Stanier, a professor of chemical and biochemical engineering at the University of Iowa who specializes in air pollution studies, agrees. “Think of smoke waves like heat waves,” Stanier notes. “They’re easier to face if you’re prepared and know they’re coming.”

Cleanup Efforts

What if an IAQ unit could compensate for the amount of particulate inside a home? 


If the number of unsafe indoor air particles increases due to outside pollution, Broan-NuTone’s BNAP-100 air purifier can compensate automatically and keep the breathing environment beneficial. Credit: Photo courtesy of Broan-NuTone

Broan-NuTone has developed an air purifier to that effect. The single-room Broan-NuTone Air Purifier (BNAP)-100’s advanced auto-sensing technology automatically detects total volatile organic compounds (TVOCs) and particulates the size of respiratory droplets, dust and pollen. It automatically and quickly increases the fan’s speed to remove detected particles and VOCs.

When the air is clean, BNAP-100 automatically reduces back to regular maintenance speed, ensuring clean air without sacrificing energy efficiency. The air purifier’s settings can be adjusted with Alexa- or Google-based devices.

A bonus: While some air filtration units on the market emit low levels of ozone—a chemical that can cause respiratory damage at a cellular level—the BNAP-100 is third-party certified to emit zero ozone.

The BNAP-100 also provides homeowners with a Clear Air Delivery Rating (CADR) of 153 for tobacco smoke, 171 for dust and 175 for pollen. (Competitor model CADRs are typically in the low- to mid-200s.) The unit includes a replaceable 3-in-1 filter (prefilter, activated charcoal and True HEPA), one that is automatically treated by built-in ultraviolet (UV) light.

Meanwhile, a California company has a product that helps with outdoor pollution caused by one of a home’s key components. Fortera’s ReAct cement is a sustainable alternative to the traditional variety, which is responsible for about 8 percent of the world’s carbon emissions, according to CEO Ryan Gilliam.

“Basic” cement, derived from limestone, is heated in a kiln, where it decomposes (a.k.a. calcinates) and creates nearly equal parts of calcium oxide (lime) and carbon dioxide (CO2 ). ReCarb captures the CO2 and mineralizes it, creating a new form of cement that has 

70 percent lower carbon emissions on a ton-for-ton basis. The mineralized CO2 is permanently removed from the atmosphere.

Fortera Redding ReCarb Plant 2

A new production facility launched by Fortera will increase the availability of its ReAct sustainable cement product to the construction industry. Credit: Courtesy of Fortera

The ReCarb process also lays the groundwork for zero-carbon cement through the use of renewable energy. ReCarb is already less energy-intensive due to a lower kiln temperature (1,650 degrees Fahrenheit vs. 2,500 degrees F), which opens a path to electrification. Fortera’s technology is synergistic with all green energy developments happening in this space—including electric kilns (which the company has patented), green energy or green fuel integration, and thermal batteries, Gilliam notes.

“Realizing zero-carbon cement is critical for our continued infrastructure and the health of our planet,” Gilliam says. “We recognize this is one step in a much larger effort to reach commercialization globally, and we are committed to scaling our technology using existing infrastructure to mobilize widespread adoption of low and zero-carbon cement.”

ReAct can be quickly and efficiently created while traditional cement is developed at existing production facilities, which provides environmental and financial benefits. In April, Fortera opened its first green cement and carbon mineralization facility in North America—next to a cement plant owned by CalPortland in Redding, Calif. More than 6,600 tons of CO2 and 15,000 tons of low-carbon ReAct cement will be produced annually.