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Environmental engineering researchers study airborne coronavirus disinfection

Graduate student Marina Nieto Caballero and visiting virology scholar Eddie Fuques Villalba, preparing to assess the infection potential of murine Coronavirus in CU Boulder SEEL-based environmental engineering laboratory.

An environmental engineering research team has been chosen to study the fate of airborne coronavirus indoors. 

Environmental engineering researcher Odessa Mason Gomez prepares a large chamber to contain aerosolized coronavirus. Gomez is part of an interdisciplinary bioaerosol research team that is studying the stability of the novel coronavirus under different environmental conditions, including exposure to UV light and aerosolized disinfectants.

The team, led by Professor Mark Hernandez, also includes graduate students Marina Nieto Caballero and Emma Biesiada and visiting scholar Eddie Fuques Villalba. Postdoctoral fellow Mariana Lopes, who recently graduated from Arizona State University, will join the team this month, with a focus on novel coronavirus disinfection in building ventilation systems.  

Two environmental engineering alumni, Odessa Mason Gomez (PhDEnvEngr’16) and Sara Beck (PhDEnvEngr’16) have also returned to CU Boulder to help guide the effort. 

“Several hospitals and industrial partners have approached us since the pandemic broke out,” Hernandez said. “These collaborators include Denver Children’s Hospital and multinational corporations like the Clorox company and Carrier Corp. Philanthropy is playing a big support role here as well, but they wish to remain anonymous at this point.”  

Hernandez's research team is also working with Colorado’s technology sector, including Aerosol Devices of Fort Collins and DetectionTek of Boulder. They received a new RAPID grant from the National Science Foundation to support their COVID-19 characterization studies, with support from the National Institutes of Health pending. 

Hernandez’s lab has been researching the characterization and control of airborne microorganisms for almost 25 years. Most recently, they have been monitoring the aerobiology in metropolitan mass transportation systems around the world, as well as local public schools.

Visiting Scholar and Virologist, Eddie Villalba, checks on the progression of Coronavirus infection in mouse liver cells.

The research on COVID-19 persistence is in response to a need for modernizing indoor disinfection delivery and assessment frameworks, along with associated industrial hygiene practices, said Hernandez. The study aims to test airborne coronavirus disinfection responses using the large bioaerosol chamber in Hernandez lab. Surface disinfection studies are also underway.

 

“We are using classic methods for culturing mammalian viruses as well as emerging instrumentation from the Colorado tech sector that helps them characterize the identity, distribution and infectious potential of indoor airborne microorganisms — notably including coronavirus,” Hernandez said.

Instead of using the human pathogen, SARS-CoV-2, the researchers are using two model viruses. One is a mouse coronavirus virus (MHV) that is closely related to COVID-19 but only infects mice. It has been previously validated as a surrogate for the environmental persistence and disinfection response of the coronavirus subgroup. The other is the MS2 coliphage, which has been used as an indicator for many air and water disinfection studies. 

Hernandez’s team will be testing how well common air disinfectants — including the “foggers” that spray peroxides, chlorine derivatives and surfactants — work against these model viruses. 

“The goal of this research is to optimize large-scale aerosol disinfection systems and commercial cleaning protocols in ways that help mitigate the persistence of coronavirus in our built environment,” Hernandez said.