Air quality level inside average U.S. home may be comparable to ‘polluted major city,’ shocking study finds

Research shows that common household activities, including cooking and cleaning, cause harmful particulates to enter the “esosphere” and worsen indoor air quality.

WASHINGTON — Just when you thought staying in was one way to avoid pollution from surrounding cities and heavy road traffic, a new study is sounding the alarm on the cleanliness of the air inside our own homes.

Researchers from the University of Colorado Boulder say the average house is prone to “indoor air quality levels on par with a polluted major city,” and everyday activities like cooking and cleaning may be to blame. The authors believe that chemicals found in common household substances are even seeping outdoors, creating more air pollution than cars and trucks do.

“Homes have never been considered an important source of outdoor air pollution and the moment is right to start exploring that,” says Marina Vance, an assistant professor of mechanical engineering at the university, in a media release. “We wanted to know: How do basic activities like cooking and cleaning change the chemistry of a house?”

So the researchers connected a network of air quality sensors inside a 1,200-square-foot manufactured home on the University of Texas campus in Austin during the summer of 2018. Vance and her team occupied the house over a month, carrying out daily activities such as cooking meals and cleaning up the place with common goods. They even recreated a traditional Thanksgiving dinner.

Preliminary results from the study show that air quality levels were so poor at the end of the study, the researchers had to recalibrate their sensitive instruments almost immediately. The shocking finding led the researchers to suggest American homes need to be better ventilated, particularly when residents are cooking and cleaning. Boiling water on a gas stove, for example, led to higher levels of harmful particulates and gaseous pollutants.

“Even the simple act of making toast raised particle levels far higher than expected,” notes Vance. “We had to go adjust many of the instruments.”

The authors say research on air pollution typically focuses on outdoor sources, while few studies have noted the dangers of compounds emanating from homes. They hope their findings will lead to more work surrounding the “esosphere,” a lesser-known term derived from the Greek word “eso,” meaning “inner.”

“There was originally skepticism about whether or not these products actually contributed to air pollution in a meaningful way, but no longer,” says Joost de Gouw, a visiting professor at Colorado Boulder’s Cooperative Institute for Research in Environmental Sciences. “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.”

The results of the study were presented at the American Association for the Advancement of Science Annual Meeting in Washington, D.C.