A recent study published in Indoor Air from the University of Colorado Boulder has found that the emissions that humans emit when exercising may impact indoor air quality. Notably, the data for this study were gathered prior to the coronavirus pandemic, yet its findings may help guide protocols about exercise inside gyms and other workout facilities.
"Humans are a large source of indoor emissions," said lead author Zachary Finewax, who is a CIRES research scientist. "And chemicals in indoor air, whether from our bodies or cleaning products, don't just disappear, they linger and travel around spaces like gyms, reacting with other chemicals."
"Since people spend about 90 percent of our time indoors, it's critical we understand how chemicals behave in the spaces we occupy," explains corresponding author Joost de Gouw, CIRES Fellow, professor of chemistry at CU Boulder.
According to the researchers, humans emit five times as many chemicals while exercising compared to sedentary behavior. As Finewax alludes, these chemicals include amino acids from sweat or acetone from breath – but they also include cocktails of airborne chemicals that form when amino acids and acetone mix with the chemicals of personal hygiene products and cleaning products like bleach.
The researchers collected air sample data from a weight room in the UC Boulder Dal Ward Athletic Center. They measured airborne chemicals in real-time before, during, and after workouts of CU athletes.
"Using our state-of-the-art equipment, this was the first time that indoor air analysis in a gym was done with this high level of sophistication. We were able to capture emissions in real-time to see exactly how many chemicals the athletes were emitting, and at what rate," said co-author Demetrios Pagonis, postdoctoral researcher at CIRES.
The researchers noticed a new group of chemicals called N-chloraldimines in their samples. These chemicals were forming as a reaction product of bleach cleaning supplies with amino acids from sweat. It is still unclear how N-chloraldimines might affect indoor air quality, but the scientists warn that chemically similar reaction products of ammonia with bleach can be harmful to human health. They plan to continue investigating their research in order to better understand how human chemistry mixes with chemical products to impact indoor air pollution.