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An Invisible Enemy Researchers respond to the Covid-19 pandemic
from 2019-2020 Annual Report | School of Civil and Environmental Engineering
by School of Civil and Environmental Engineering at Georgia Institute of Technology
AN INVISIBLE ENEMY
Civil and Environmental Engineering researchers are tackling the global Covid-19 pandemic from all angles
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Covid-19 has affected just about every aspect of our lives. In our efforts to combat the highly contagious virus, we have changed the way we work, the way we study, the we travel, and more.
Civil and environmental engineers are uniquely prepared to analyze every aspect of this global crisis. In fact, it’s in our School’s mission statement: We are leaders in systems-level thinking and technological innovation that define and solve complex problems at the interface of built, natural, and social systems.
The coronavirus pandemic illustrates the breadth of expertise held by our CEE faculty. From studying air and water quality, to telecommuting, transit ridership and infrastructure resilience, researchers from the School of Civil and Environmental Engineering have mobilized quickly to help find solutions to our current crisis and study the lessons that can be applied to the future. Read on to see how these engineers are stepping up to help us make sense of this unprecedented global phenomenon.
Wastewater-Based Epidemiology
Joe Brown, Carlton S. Wilder Assistant Professsor
Associate Professor Joe Brown is among 60 researchers who have created a global collaborative to learn more about the spread of Covid-19 through wastewater.
In a paper published in Environmental Science & Technology, the researchers explained that RNA from the coronavirus is shed in the feces of those infected with Covid-19. This allows researchers to survey sewage for virus RNA, a process they refer to as wastewater-based epidemiology (WBE).
Covid-19 RNA has been detected in wastewater during the early stages of outbreaks, meaning that wastewater-based epidemiology could be a powerful tool for alerting communities of an outbreak before it gets out of control.
What has made the coronavirus so insidious is that it can be spread by people who are infected but exhibit no symptoms. However, wastewater samples provide a community aggregate that shows evidence of the virus – whether individuals are symptomatic or not.
Brown explained that the researchers are pairing their virus RNA measurements with available
Joe Brown
Covid-19 testing data from the same areas to evaluate whether wastewater signals can provide an advance warning of an outbreak.
“Wastewater detection of viral RNA can give us a four-to-seven-day lead time on increases or decreases in infection, since shedding of the virus in fecal waste begins before symptoms appear,” Brown said.
Brown has been working with colleagues from Georgia Tech and Emory University to collect samples at sewage treatment plants in the Atlanta metro area since March 2020.
“Our approach has the potential to fill gaps in testing, and we’re excited about the prospect of applying these methods over smaller scales, like for long-term care facilities, prisons, schools, or dormitories on campuses, where monitoring is still limited and early detection of impending outbreaks would be highly valuable,” Brown said.
Brown is collaborating with a large, dynamic, and growing group of scientists, engineers, and public health professionals on methods and interpretation of results, both across the US and internationally.
A major platform for collaboration and communication on this topic is being led by Aaron Bivins, CE 07, MS EnvE 15, Ph.D. EnvE 19, who was part of Brown’s research group at Tech and now serves as a postdoctoral research associate at the University of Notre Dame.
Brown said it has been a meaningful experience to work together with so many other researchers around the world.
“It’s been exciting. We’re part of this global effort to bring our best science to understand and control this virus, and the stakes could not be any higher. I’m hopeful that our work can be part of the solution,” Brown said.
Wastewater Disinfection
Environmental Engineering Professor Ching-Hua Huang is devoting some of her research efforts to address one of the unknown effects of the coronavirus pandemic: how thoroughly the virus is treated in wastewater.
Huang’s research group is working on a National Science Foundationfunded project to investigate disinfection processes for wastewater treatment.
“We are very interested in knowing how well the wastewater treatment process can handle coronavirus,” Huang said.
Currently, chlorine is the most commonly used disinfectant in wastewater treatment. While it is effective, chlorine also creates harmful byproducts.
So Huang and her research group are studying the effectiveness of organic peroxides, a group of chemicals with fewer toxic byproducts that can also be good disinfectants. Huang is working with peracetic acid in particular.
Peracetic acid is already approved in the U.S. for wastewater and stormwater treatment and is also used as a disinfectant in sectors including food processing, the medical field, and the paper and pulp industry.
In published studies using bacteria, Huang and her students have found that combining the peracetic acid with UV light results in very effective disinfection. Currently, Huang’s research group is exploring how effective this disinfection strategy could be against viruses as well. Her group is investigating different bacteriophages, which are suitable surrogates for the coronavirus and other types of viruses.
The goal of her study is to advance the fundamental knowledge on organic peroxides and develop better treatment processes to mitigate water pollution to protect public health and environmental sustainability.
So far, Huang says the disinfection studies are very promising for the coronavirus surrogate dispersed in wastewater.
“The results we learn from them will be very useful,” Huang said.
Ching-Hua Huang
Monitoring Air Quality
The airline industry has undoubtedly been one of the hardest-hit by the coronavirus as people abandoned trips on tightly packed airplanes to avoid exposure.
This almost immediate world-wide drop in air travel in early 2020 presented researchers with an unprecedented opportunity to study how emissions from air travel affect the air we breathe.
Assistant Professor Jennifer Kaiser and Adjunct Professor Sally Ng have set up two measurement sites to track changes in air quality resulting from the Covid-19 response.
At the first site, on the Ford Environmental Science &Technology rooftop lab at Georgia Tech, Kaiser and Ng are using a set of instruments to make chemically detailed measurements of air pollution, allowing them to dig deeper into reaction mechanisms and test our current understanding. This measurement site is representative of the average air quality close to the urban core.
The second site is located near Hartsfield-Jackson Atlanta International Airport. There, Kaiser is using a more limited set of instruments to target nitrogen dioxide and formaldehyde. These two pollutants are visible from satellite-based instruments and can be used to map air quality.
“Satellites see a hot-spot of nitrogen dioxide and formaldehyde right at the Atlanta airport,” Kaiser said. “The instruments we’ve deployed are designed to see if ground-based observations track with satellite-based observations. Changes in aviation traffic during Covid-19 allow us to observe a large range of emissions and concentrations in a short period of time.”
Often cited as the world’s busiest airport, Hartsfield-Jackson has undergone a dramatic decrease in air traffic in 2020.
For example, the Atlanta Journal Constitution reported that the total number of flights at Hartsfield-Jackson International declined 73 percent in April 2020 compared with April 2019, according to the airport’s monthly air traffic report. The Atlanta airport handled 20,406 flights in April 2020, down from 75,669 in April 2019.
Kaiser said their measurements over the summer show this pattern has made an impact.
Observations of nitrogen dioxide over Atlanta reveal that the airport hot-spot is no longer as distinct—the overall magnitude has decreased, but also, the spatial pattern has dramatically changed.
While Kaiser and Ng still need to analyze the data, they report that air quality has indeed improved during 2020.
“We’ve had less days with poor air quality this summer compared to the previous five-year average,” Kaiser said.
Jennifer Kaiser
Sally Ng
Telecommuting Past, Present and Future
Patricia Mokhtarian, the Susan G. and Christopher D. Pappas Professor in the School of Civil and Environmental Engineering, was uniquely prepared to analyze the nation’s massive shift to telecommuting due to the coronavirus pandemic.
Mokhtarian has been studying the adoption and travel-related impacts of information and communication technologies, including teleworking, since 1982. She has also authored more than 40 peerreviewed articles related to teleworking and recently served as chair of the International Association for Travel Behavior Research.
“I have been studying teleworking nearly 40 years now, and during those past four decades there has been a steady stream of predictions about the pending ubiquity of working from home,” Mokhtarian said.
There have also been a variety of events during her career, whether natural or human-caused, that have led to increases in teleworking such as transit strikes, earthquakes, Olympic Games, terrorist attacks and bridge collapses.
“It seems that history repeats itself with each one of these extreme events,” Mokhtarian said. “We have lots of people teleworking during the event and the aftermath and there’s lots of chatter about how ‘now that everyone sees how great teleworking is, it’s going to take off rapidly.’”
But the reality is that aside from these extreme events, the percentage of the workforce that telecommutes full-time has remained small over the years—just 5.3 percent reported that they usually work from home, as recently as the 2018 American Community Survey.
Due to Covid-19, those numbers have spiked rapidly. Depending on the poll, roughly 40-60 percent of the workforce reported working remotely during the spring of 2020.
So many, including writers from major publications, have turned to Mokhtarian for her prognostication: Will this time be different?
“Some key reasons for the slow adoption of working from home have not gone away,” Mokhtarian says.
While there are many benefits to telework—no commute, more flexibility— working from home presents constraints and challenges for others, such as isolation or a lack of comfortable work space. Mokhtarian points out that it’s also important to remember that about 40 percent of workers, such as cashiers and hair stylists, don’t have the option to telecommute.
“The likely reality is that we will not go back to the way things were, but we won’t remain at these emergency levels of teleworking indefinitely,” Mokhtarian said. “I believe if nothing else the pandemic will have given us a very clear idea of the pros and cons of teleworking for employees and organizations.”
Patricia Mokhtarian
Lessons in Resilience
Professor Adjo Amekudzi-Kennedy
What happens when something comes along and challenges our bedrock assumptions about systems in society?
Professor Adjo Amekudzi-Kennedy studies infrastructure resilience—the ability of critical systems to resist and recover quickly from major disruptions, adapt to changing circumstances and bounce back more quickly from disasters—be they natural, humancaused, or in this case, viral.
In April, Amekudzi-Kennedy led the development of an article that considers the infrastructure and sustainable development implications of the Covid-19 pandemic, along with colleagues from Georgia Tech, Purdue University and Arizona State University.
The researchers examined the pandemic through the lens of transportation infrastructure and came up with five lessons that can be learned from the Covid-19 pandemic:
Adjo Amekudzi-Kennedy
Transportation planning must be comprehensive
for long-term sustainability. The rapid spread of the coronavirus revealed how critical threats can pose risks to sustainable development. While mass transit has long been considered a sustainable option for reducing carbon emissions, the pandemic has shown mass transit’s vulnerability: lost ridership as people have fled transit to avoid contracting the virus.
We need multiple modes of transportation to be
most resilient. Covid-19 is teaching us that perhaps it is not so much about one mode versus another, or which transportation mode is best from only one perspective. Rather, there is wisdom in planning for and investing in a robust multimodal transportation system that offers multiple convenient and costeffective choices.
Less can be more when it comes to travel
and resiliency. The rapid national movement to teleworking and remote learning during the Covid-19 pandemic is causing many to ask questions about how essential it is to travel back and forth on a daily basis for work and school. More people working remotely in the long run could lead to less congestion, traffic and pollution. However, the digital divide means that not all people can choose to work from home.
Economic capital is key. The authors cite the more than $2 trillion U.S. coronavirus relief package passed by federal lawmakers as evidence of the need for economic resiliency in the face of critical threats to sustainability.
Social capital is just as crucial. Covid‐19 has demonstrated the importance of the global community mobilizing and acting quickly around sustainable development risks. Whether in the case of fast‐moving disasters like Covid‐19 or slow-moving disasters like climate change, it’s important for people to work together before it’s too late. 39
