A panel at the latest American Association for the Advancement of Science conference held in Washington D.C. last week revealed some startling new information about the chemicals and particulates found inside homes and their potential to wreak havoc on human bodies, especially small ones.
The studies presented at the session, titled "Homes at the Center of Chemical Exposure: Uniting Chemists, Engineers, and Health Scientists" showed that pollutants can be released into your home by everything from cooking to cleaning to the filler inside your furniture. Some of these chemicals and particulates have been linked to thyroid disorders, respiratory issues, and cancers.
Marina Vance from CU Boulder’s Department of Mechanical Engineering and Visiting Professor Joost de Gouw of the school’s Cooperative Institute for Research in Environmental Sciences (CIRES) spoke about household products and cleaners that emit air pollutants. Their research took place in an uninhabited 1,200-square-foot test home built as part of a collaborative project with the University of Texas Austin.
Vance, who has long been a part of the project, called HOMEChem, used advanced sensors and cameras to monitor the indoor air quality over the course of a month. The scientists conducted daily household activities including cooking and cleaning in the home and measured their effects on air quality. According to Vance, "We wanted to know: How do basic activities like cooking and cleaning change the chemistry of a house?"
Of course, we all live in homes where cooking and cleaning takes place on a daily basis, so what's the big deal? Well, it turns out the chemical compounds emitted by these activities get into your body from breathing the air, eating the food you produce, and touching your furniture.
The final results of the study are still pending, but allowed the researchers to report that
...routine household activities generate significant levels of volatile and particulate chemicals inside the average home, leading to indoor air quality levels on par with a polluted major city.
Even tasks as simple as boiling water over a stovetop flame could contribute to potentially dangerous levels of gaseous air pollutants and suspended particles. "Even the simple act of making toast raised particle levels far higher than expected," Vance said.
Gouw, also from UC Boulder, pointed out that while we often think about vehicles as a major source of air pollution, clean air advocates have ensured improvements in that area. In the meantime, we’ve seen chemicals used indoors such as cleaners, glues, coatings, and personal care items become a much larger source of volatile organic compounds (or VOCs).
He said while some pollutants (like ozone and fine particulates) are monitored by the EPA:
“...data for airborne toxins like formaldehyde and benzene and compounds like alcohols and ketones that originate from the home are very sparse."
But it’s not just your cleaning products or your cooking choices that lead to airborne toxins. Heather Stapleton, an environmental chemist at Duke's Nicholas School of the Environment, also told the audience that her research showed that semi-volatile organic compounds (SVOCs) were commonly found in the bodies of children living in homes with vinyl flooring as well as couches and chairs that contained flame-retardant chemicals.
While the Boulder researchers used their test house to perform reseach at will, Stapleton and her team tested children that were already living in homes with these risk factors.
Despite the fact that SVOCs are widely used in everything from electronics to furniture and “can be detected in nearly all indoor environments," Stapleton said "there has been little research on the relative contribution of specific products and materials to children's overall exposure to SVOCs."
In this project, Stapleton and her colleagues from Duke, the CDC, and Boston University examined 203 children from 190 families between 2014 and 2016 to measure in-home exposure to these chemicals by collecting samples of indoor air, indoor dust, and foam from furniture in each of the children's homes. They also took a hand wipe sample, urine, and blood from each child.
(Of course, all U.S. researcher who work on humans, and especially on children, are required to have their research approved by an ethics board and provide some sort of resources to families who participate.)
When testing the blood and urine, scientists used 44 biomarkers to see if the samples indicated exposure to toxins. In homes where the living room sofa contained flame retardant materials (specifically flame-retardant polybrominated diphenyl ethers, or PBDEs) children had a six-fold higher concentration of that chemical in their blood. Children from homes that had vinyl flooring in every room (although that was only 9% of homes) were found to have concentrations of a compound called benzyl butyl phthalate (BBP) metabolite in their urine that were 15 times higher than those in children living with no vinyl flooring.
While most of the studies on these chemicals' role in diseases have not demonstrated a conclusive causal relationship and therefore require more evidence, PBDEs have been linked to neurodevelopmental delays, obesity, endocrine and thyroid disruption, and cancer. BBPs have been linked to respiratory disorders, skin irritations, multiple myeloma, and reproductive disorders.
"There was originally skepticism about whether or not these products actually contributed to air pollution in a meaningful way, but no longer," de Gouw said. He continued:
"Moving forward, we need to re-focus research efforts on these sources and give them the same attention we have given to fossil fuels. The picture that we have in our heads about the atmosphere should now include a house."
While neither Stapleton nor Vance could be reached for comment on steps we can take to prevent harm done by poor indoor air quality, the World Health Organization has long recognized the dangers of this pollution, especially on children, and recommended good ventilation while cooking, the use of lids on pots and pans, cleaning cooking areas, and keeping children away from smoke to protect them.
But the research also leaves us wondering how to maintain our lifestyles and keep a clean home if even cleaning products can have deleterious effects on health. It's difficult to crack a window in the winter or in an area where outdoor pollution is also a problem. Children touch things all the time in stores, schools, and other people's homes that we have no control over. Asking people to replace their vinyl flooring or purchase a couch without flame retardant materials isn't always economically viable.
The Asthma and Allergy Foundation of America lists even more sources of household pollutants that can affect air quality. While they include a long list of things we can do to improve that quality (but note that this information is sponsored by Dyson), taking all of the recommended steps could seem overwhelming, and the furniture guidelines could require large investments (for example, discarding throw pillows, using only washable curtains, purchasing leather or vinyl sofas and chairs, and replacing carpets with low-VOC flooring, etc.).
However, some of the steps recommended by agencies across the world can provide a useful start on getting into new behaviors, including paying attention to the materials any new home items you purchase are made of. Next time you purchase cleaning supplies, you can get unscented and non-aerosol versions. And you can air out your home when the weather (and other conditions) permit. Sadly, you'll probably want to remove candles and air fresheners from your home if allergies and asthma are potential problems. And when you have the money, you can also invest in air filters, especially for areas where pets and children spend time.
Unfortunately, manufacturers are not currently obligated by U.S. law to list all ingredients in consumer products and labels such as "natural" or "green" do not necessarily mean the products are safer. Better air quality will require some research on your part, and it's best to find a reliable source of information(not a manufacturer's website, which is devoted to marketing their products to you). One place to start is the EPA's Safer Choice website, that lists products that have been evaluated by scientists for safer ingredients and more honest labeling.
I earned a Ph.D. in History and Philosophy of Science in 2013 and work as a writer and consultant on a wide range of topics including the ethics of science, technology, and medicine; science and pseudoscience in the wellness industry; national security; and diversity the workplace. My work has appeared in international news and trade outlets, though most of my time is spent working closely with multinational corporations on responsibly translating technical information for the public.