Young Innovators: USask student uncovers hidden risk in cleaning products

University of Saskatchewan (USask) PhD Candidate Pedro A. F. Souza is investigating some unexpected impacts of using common household cleaners on indoor air quality. Specifically, he is looking to understand how certain cleaning products and conditions compromise our indoor air quality.

“My research has shown that the way we clean, and the type of light used in a room can really change the air we breathe indoors,” said Souza. “I found that using certain cleaning products under specific lighting conditions like sunlight or fluorescent lights can create reactive chemicals that can drastically affect indoor air quality.”

Souza is part of the Kahan Laboratory in the Department of Chemistry. Led by Dr. Tara Kahan, the team studies chemical reactions in the environment and atmosphere, using specialized tools to understand and predict the reactions happening in parts of the environment like ice, oceans and indoor air.

“Indoor air chemistry is a relatively new field of study that began to take off in the 1990s so there are many aspects of my research that can be considered a new approach — from the tools used to monitor pollutants to the mathematical prediction,” said Souza. “But the most unique thing about my research is understanding the complex chemical processes driven by light in indoor environments.”

Souza is particularly interested in the use of germicidal ultraviolet (GUV) light and its use alongside cleaning products containing bleach. GUV is a type of light that sanitize surfaces and air by killing bacteria, viruses and fungi. GUV lights have been used for sanitation in industrial and institutional settings like hospitals for decades but became popular and more accessible to individuals during the COVID-19 pandemic. Anyone can purchase a GUV light online and use it as part of their cleaning routine.

“Bleach has compounds that are highly reactive and can be broken down by UV light. We’ve measured that bleach emissions produce powerful oxidants indoors when exposed to GUV,” said Souza.

When inhaled, these compounds can get deep into your lungs and can cause serious health risks. But Souza says that there are easy ways to protect your lungs and improve air quality while cleaning.

“The first thing you need to do is ensure there is ventilation. That can be as easy as opening a window if you’re cleaning your home or turning on the bathroom fan,” said Souza. “If you have continuous air exchange during a cleaning event you are going to be breathing in a lot less chemicals.”

If you’re thinking that running an air purifier will help, Souza says that these devices are not an effective tool against harmful chemicals.

“Air purifiers can’t trap these kinds of compounds, so they don’t really work to help keep the air clean in this case. We’re still investigating the reactions involving these molecules, but it’s complicated, the composition of chemicals in the air changes very fast and it’s very tricky,” said Souza.

Solving tricky challenges like this is something that initially drew Souza into chemistry. He credits his undergraduate research advisor Dr. Arnaldo A. Cardoso from the Institute of Chemistry of Sao Paulo State University (UNESP) in Brazil, who showed him not only the importance of investigating and understanding atmospheric and environmental chemistry but also the fun parts of the analytical process.

“What keeps me driving forward is not only my curiosity and interest but the research possibilities,” said Souza. “There are so many unknowns regarding indoor air chemistry, and I know how impactful this work can be — helping people evaluate their cleaning habits and make informed decisions that can help them breathe healthier while indoors.”