In the time it takes to type this sentence, I will have taken three breaths. Twelve in a minute, 20,000 a day, 7.5 million a year, most of them indoors. Yet until quite recently, researchers have not paid much attention to the quality of indoor air.
“It used to a be a pretty robust field, dominated by airborne infectious disease transmission, up until the 1960s,” said Richard Corsi, dean of the UC Davis College of Engineering. Ironically, the growing environmental movement, passage of the Clean Air and Clean Water Acts and the formation of the Environmental Protection Agency, all in the 1970s, moved the focus to outdoor pollution.
“The Clean Air Act was focused entirely on outdoor air and trying to reduce the amount of smog and other air pollutants in cities,” Corsi said.
The COVID-19 pandemic marked a significant change, prompting scientists and engineers to unravel the complex factors that go into indoor air quality. UC Davis researchers are studying ways to optimize the flow of outdoor air into buildings for both energy efficiency and reducing exposure to pollutants, and are taking a close look at how viruses and other pathogens travel from person to person via indoor air currents. Their work could mean better health at home and increased productivity at work.
Indoor exposure to air pollution
Corsi brought his work indoors in the 1990s.
“I was doing outdoor air work and I realized how little work had been done on indoor air, realizing that most of our exposure to pollution of outdoor origin happens when we're inside,” he said. “And you add this interesting chemistry and microbiology that's happening indoors, it's like a wide open frontier. It just excited the heck out of me.”
Corsi chaired a National Academies of Sciences, Engineering, and Medicine committee, which last year urging action to reduce indoor exposure to ultrafine particles, known as PM2.5, especially in schools.
Epidemiological studies of outdoor air pollution have shown a clear link to human health. But most of that exposure to outdoor pollution actually occurs indoors, because outdoor air pollutants infiltrate indoors where most Americans spend most of their time.
“We're exposed to things where we are, and we spend more time indoors than we do outdoors,” said Deborah Bennett, professor in public health sciences and at the UC Davis Environmental Health Sciences Center.
Air quality and energy efficiency
At the Western Cooling Efficiency Center at UC Davis’ West Village, Engineering Manager The