This article, Ensuring Passenger Health on Buses and Public Transportation, was published in School and Metro Bus Magazine for client AFFLINK
This article is being written the last week of 2020, one of the most challenging and disruptive years for buses and public transportation. The coronavirus has impacted transportation systems and people throughout the world.
It took some time to fully understand the virus and how it spreads, and in the process, there was much misunderstanding and misinformation. For instance, if you remember, back in March—it seems so long ago—the Centers for Disease Control (CDC) and other health experts in the U.S. instructed us not to wear masks. Health and Human Services Secretary Alex Azar said, “Our advice remains as it has been that the average American does not need an N95 mask. These are more for health care providers.”1 
Of course, now we know that masks are our most significant defense against the virus. Some public health officials are even recommending that for added protection, people in certain age groups continue wearing masks even after they have been vaccinated.
As to stemming the spread of the virus, there was also confusion about how long it lived on surfaces and whether the virus could be transmitted from surfaces to people. Regarding the virus’s lifespan on surfaces, most experts now agree it can survive on surfaces for a few hours to a few days, depending on the type of surface, how frequently it is touched, and other conditions.
As far as being transmitted to people from surfaces, the CDC reported in May that the virus is “mainly spread by inhalation” and was not as likely to spread by touching surfaces. However, since then, they have backtracked, indicating that this virus, just like so many others, can be transmitted by touching a contaminated surface and then touching our eyes, nose, mouth, or food that is later consumed.
There is the possibility for even greater transmission of the virus if these contaminated surfaces are touched frequently. These are known as “high touch” surfaces, and that’s where buses—both school and metro—as well as most all types of public transportation vehicles, come into the picture.
For instance, in a school or metro bus, it may be challenging to find a surface that is not a high-touch surface. Windows, ledges, railings, poles, straps, seating areas, you name it, are touched repeatedly throughout the day by passengers. Further, bacteria and virus can mutate faster on these surfaces than a cleaning crew can manually disinfect them, further increasing the difficulty of protecting passengers and drivers from exposure.
To help stop the spread of the virus, we need to do all we can to keep these surfaces clean and disinfected. If performed manually, this is a very time-consuming process. In most cases, surfaces must be cleaned first and then disinfected, a two-step process. Further, this methodology requires using large amounts of cleaning solutions and disinfectants. Because disinfectants in the U.S. are not green-certified, such large amounts can potentially harm the user, passengers, and indeed the environment.
To address this, during the early months of the pandemic, many transportation organizations began looking into other cleaning and disinfecting options. Two that have surfaced to the top, have proven their efficacy and effectiveness, and have shown to have a reduced impact on the user and the environment, are UV-C and electrostatic sprayer technology. We will discuss each of these technologies below and how they can be used specifically on school and metro buses.
UV-C and Buses and Public Transportation
On May 19, 2020, the Metropolitan Transportation Authority (MTA) in New York announced that they would begin using ultraviolet (UV) light to kill COVID-19. Over time, it would be phased in on subways, buses, and other New York transit vehicles throughout the system. As to why they selected this technology, the MTA said the following:
UV-C light is an efficient, proven, and effective technology for eliminating viruses, including SARS-CoV-2 that causes COVID-19, from surfaces in MTA’s system. UV-C is demonstrated to kill viruses in many other applications, including hospital operating rooms, urgent care clinics, universities, and fire stations.
They also reported that the UV-C systems will first be used on the administration’s “rolling stock” overnight, when the transit vehicles are not in use, and then be used in “occupational facilities, including maintenance areas, crew rooms, operations and technology centers, and offices,” for disinfection purposes throughout the MTA system.
Before explaining this technology further, some things need to be clarified. According to Karl Linden, a professor of environmental engineering at the University of Colorado, here are a few things we should know:
- Ultraviolet light is not new. It has been used for disinfecting purposes in hospitals, clean rooms, and transit vehicles for decades.
- Ultraviolet light is electromagnetic radiation, which includes radio waves, visible light, and x-rays. These are measured in nanometers.
- UV is divided into UV-A (315–400 nanometers), UV-B (280–315 nanometers), and UV-C (200–280 nanometers).
- Of the three types, UV-C is the most effective at killing pathogens.
As to how it works, UV-C is absorbed into the DNA and RNA (ribonucleic acid) of pathogens. As it is absorbed, it renders the genetic material inside the microorganism unable to replicate or cause an infection, essentially inactivating the pathogen.2
Along with proven efficacy, up to 99.9 percent, among the other benefits of UV-C are the following:
- It eliminates the need for any cleaning solutions, a major cost savings.
- Along with the pathogens that cause coronavirus, UV-C is a “microbial,” it can kill many types of disease-causing pathogens.
- The technology promotes sustainability; fewer materials need to be packaged, transported, or manufactured.
- Depending on the system, it can provide 360 degrees of coverage up to 10 feet from the unit. Often the unit is moved through a transit vehicle via remote control.
- When used properly, it is perfectly safe.
- Because no cleaning solutions are used, there is no impact on the user or the environment.
- When used, a larger area is disinfected at one time, reducing time and labor costs.
According to Linden, as we learn more about the potential for UV-C, more uses for UV-C and fighting the spread of COVID are likely to be uncovered. He believes UV-C systems will be added to HVAC systems, to disinfect air in all types of facilities, as well as transport vehicles. This means UV-C technology can be used both for disinfecting surfaces as well as disinfecting the air we breathe.
Electrostatic Sprayers
Electrostatic sprayers are also not new. They were developed in the 1930s and used primarily for industrial spraying and coating of equipment and machinery. These systems spray a disinfectant onto surfaces. In most cases, these surfaces must be cleaned first before the spray can be applied, which is not always necessary with the UV-C technology just discussed.
As the disinfectant spray or “mist,” as it is often called, is released by the machine, it places a negative electrical charge on the disinfecting solution as it goes out the nozzle. Because most surfaces in a transit vehicle or facility are neutral or positively charged, this helps ensure the mist adheres to these surfaces.3 Doing so, it starts to kill or deactivate pathogens within seconds.
In many ways, this technology has the same or similar benefits of the UV-C technology. For instance:
- It is also a labor saver, because large areas can be covered and disinfected at one time.
- This also reduces time, making it a cost savings.
- While it is recommended that the user wear gloves and goggles, these systems are safe if used properly.
- Fewer cleaning solutions are used, reducing cleaning’s impact on the environment and promoting sustainability.
- They can kill or deactivate a wide range of microbials, not just those related to the coronavirus.
What we are witnessing now is that both technologies are being used in all types of transit vehicles and facilities to help eliminate the pathogens that cause coronavirus. In fact, some cleaning experts and public health professionals suggest both technologies should be used together to help stop the spread of this disease.
This way, if any pathogens are missed using one system, the second will likely catch them, ensuring our public transit systems promote health and helps us get through this difficult time as safely as possible.
Michael Wilson, vice president of marketing for AFFLINK, a distributor-membership organization that now markets electrostatic sprayers and other products designed to protect human health. He can be reached at wmwilson@afflink.com
U.S. health officials say Americans shouldn’t wear face masks to prevent coronavirus—here are three other reasons not to wear them. MarketWatch, March 3, 2020.
“Ultraviolet light can make indoor spaces safer during the pandemic—if it’s used the right way.” Karl Linden, University of Colorado, Boulder, September 9, 2020.
Coulomb’s law: Like charges repel each other; unlike charges attract. Thus, two negative charges repel one another, while a positive charge attracts a negative charge or vice versa.
