University researchers in the Central Valley have identified technologies that they say will wipe out just about every speck of coronavirus passing through air-handling systems on buses.
But transit operators, while excited at the prospect of making bus travel safer for passengers and drivers, say it could take months or even a year before the technologies can be up and running.
By then, we might all be lining up for a coronavirus vaccine.
In the meantime, face masks, hand-washing, and social distancing are still the best way for passengers and drivers to keep themselves safe, the researchers told reporters Wednesday.
But even after the pandemic fades away, the technologies identified by Valley researchers can help scrub future flu and cold viruses from bus air-handling systems.
Several Technologies Effective
The study, which was led by the Fresno State Transportation Institute, first tested air flow in buses and then introduced actual viruses — the kind that harm bacteria, not humans — to see which technologies were most effective in wiping out viruses.
Aly Tawfik, associate professor of civil engineering in the Lyles College of Engineering and director of the Fresno State Transportation Institute, said the researchers want to spread the word throughout the transportation industry of what can be done to make buses safer.
Tawfik partnered with Deify Law, an associate professor of mechanical engineering at Fresno State, and Juris Grasis, an assistant professor of molecular and cell biology at University of California, Merced, on the study.
They identified several successful virus scrubbers, including photo-catalytic oxidation inserts, a type of air purifier that eliminated 99% of viruses from buses’ heating, ventilation and air-conditioning systems, and ultraviolet light, which removed almost 98%. Maintaining higher air pressure inside the bus removed 100% of viruses found on surfaces.
Copper foil tape and copper-infused fabric eliminated 99.7% of one virus but were inconclusive on two others.
Ready to Board The Bus
Tawfik and other researchers on the Zoom call with reporters said they would feel safe riding in a bus where passengers are masked and the air scrubbed of viruses with the technologies they targeted.
But masks still will be needed as a barrier for virus particles that haven’t yet been swept through the HVAC system.
The researchers are hopeful that making buses safer will encourage passengers to return. Many bus systems nationwide are carrying a fraction of their former passenger load because of fears of contagion.
In the Fresno area, bus systems are operating with fewer passengers and more safety precautions, officials said.
Fresno Area Express set a self-imposed limit of 10 passengers per bus plus the driver back in March, said Gregory Barfield, director of transportation for the city of Fresno. Officials are taking a look at expanding ridership by four or five more passengers, he said.
FAX is seeking a federal grant so the technologies in the Fresno State study can get real-world testing, Barfield said. It could take as much as a year to get the results and install the technology.
In the meantime, FAX is taking steps to sanitize buses throughout the day and every night, and passengers are required to wear masks, he said.
Retrofitting Takes Time
Moses Stites, general manager of Fresno County Rural Transit Agency, said he’s hoping bus manufacturers can quickly analyze the tech solutions and send out retrofit equipment. The agency’s buses, which come in a variety of sizes and with various power systems, were used as labs in the Fresno State study.
Electric-powered buses, for example, are wired differently than other buses, “so you can’t just start drilling into them” to install new hardware, Stites said.
Ridership over the past eight months in the Fresno area was dampened by closures designed to slow the spread of COVID-19.
Fresno County Rural Transit caters to a lot of senior passengers who stayed home when their centers closed, and FAX lost student passengers when campuses closed, officials said.