August 12, 2022
To accelerate understanding of COVID-19 and other public health concerns, the UNC Gillings School of Global Public Health routinely funds the Gillings Innovation Laboratory awards (GILs). Generously provided by the Gillings Gift in 2007, these awards support innovative and interdisciplinary research projects.
Gillings faculty have recently completed four GILs, including two from Round 6 of GIL funding and two from the special COVID-19 round of funding. The results of their work have furthered our understanding of energy storage, brain health, environmental exposures, viral transmission, pandemic response and more.
Development of osmotic ballasts to enable saltwater-based energy storage
Orlando Coronell, PhD, associate professor of environmental sciences and engineering, led a study that explored a promising new type of battery technology called a concentration gradient battery (CGB). This type of battery has the potential to mitigate factors that contribute to pollution and climate change by leveraging sustainable saltwater-based energy.
The research was co-led by Wei You, PhD, professor of chemistry and applied physical sciences and chairperson for the Department of Chemistry.
CGBs are energy storage systems made up of a series of concentrated and dilute salt solution compartments that are separated by ion exchange membranes (IEMs). The battery is charged by electrodialysis (ED), which increases the concentration gradient between these solutions, and discharged by reverse electrodialysis (RED), which allows these solutions to mix. In both ED and RED, water moves by osmosis from dilute to concentrated compartments, reducing the CGB faradaic and energy efficiency.
The research team explored methods to mitigate osmosis by using an osmotic ballast – a type of stabilizer – in the dilute solution to balance the osmotic pressure and reduce energy losses. The study team aimed to investigate the impact of ballast properties (such as size, structure and end-group) on the CGB’s efficiency. To accomplish this, they tested seven sugar compounds and five glycol compounds as osmotic ballasts in a closed-loop cell.
Of all ballasts tested, sucrose performed best. Their overall results showed that ballasts with high molecular weight generally resulted in higher efficiency and lower water transport compared with low molecular weight ballasts. The team also found that ballasts with a cyclic, non-planar structure and lower number of methyl end groups led to lower water transport.
The CGB technology explored through this GIL offers an alternative to traditional batteries (such as the lithium-ion battery) by using affordable, abundant and non-hazardous materials. This technology is very promising in expanding renewable energy supplies which would contribute to mitigating environmental pollution and climate change.
Environmental influences on early brain development
Stephanie Engel, PhD, professor of epidemiology, led a study examining the effect of environmental toxins on early brain and behavior development using state-of-the-art imaging and analysis. The study monitored exposure to harmful phthalates that babies and toddlers may be exposed to in their home or play environments, water sources, toys or other products.
Engel’s team included Associate Professor Kun Lu, PhD and Assistant Professor Julia Rager, PhD, in the Department of Environmental Sciences and Engineering, and Professor Hongtu Zhu, PhD, in the Department of Biostatistics, as well as Weili Lin, PhD, director of the Biomedical Research Imaging Center, and additional colleagues from the UNC School of Medicine.
In pilot investigations, the study team found associations between high phthalate levels and changes in brain structures and functional networks that are undergoing rapid development in the first years of life. Among several possible associations were differences in cortical surface area, white and gray matter volume, whole brain volume, and visual network connectivity that were related to the concentrations of phthalate metabolites found in infant urine. These differences often depended on the kind of phthalate that children were exposed to, and associations tended to be stronger in boys.
This innovative research was based on a relatively small number of infants and young children, so Engel’s team has secured additional funding for this work from the Environmental Protection Agency and the National Institute of Environmental Health Sciences. They are currently working on the first publication of their findings.
In addition, the funding for this GIL facilitated a collaboration with the School of Medicine to measure exposure to the fungicide azoxystrobin, which resulted in a publication titled “Detection of azoxystrobin fungicide and metabolite azoxystrobin-acid in pregnant women and children, estimation of daily intake, and evaluation of placental and lactational transfer in mice.”
Residence time and viability of coronavirus in airborne respirable particles in public spaces
Co-led by Karsten Baumann, PhD, assistant professor of environmental sciences and engineering, and Barbara Turpin, PhD, professor and chair of environmental sciences and engineering, this study examined air from UNC dorm rooms and a UNC football game to learn how to reduce the risk of exposure to infectious viruses. The team also developed the infrastructure and methods necessary to study factors that affect the viability of viruses in aerosols in a controlled setting.
Eight additional Gillings researchers from the Department of Environmental Sciences and Engineering and one from the Department of Epidemiology also collaborated on the project. This included postdoctoral fellows Megan Stallard, PhD, and Jiaqi Zhou, PhD; doctoral student Naomi Chang, MS; Assistant Professor Michael Fisher, PhD, Associate Professor Joe Brown, PhD; Professors Jason Surratt, PhD, Glenn Morrison, PhD, and Jill Stewart, PhD, and Distinguished Professor Ralph Baric, PhD.
The study team collected airborne particles (aerosols) in the rooms of three UNC students who tested positive for COVID-19 and were isolated in a dorm and analyzed these for SARS-CoV-2 molecular markers using sensitive methods. They found measurable quantities of viral particles in one of the three rooms, more than six feet from the student. This work demonstrates that it is possible for aerosol particles containing SARS-CoV-2 to be present in the air more than six feet from people who have tested positive in the last seven days. This finding is consistent with evidence that COVID-19 transmission is more likely indoors than outdoors and stresses the importance of adequate ventilation.
The team also tested the air in the concourse and stands of a high-attendance UNC football game where there was some masking and optimal ventilation. The three aerosol samples collected before, during and after the game all tested negative for COVID-19. The researchers were able to report these results to UNC Football and reinforce the importance of masking and distancing to reduce potential exposures.
This work also resulted in the development of a chamber with well-controlled, reproducible conditions, which can help researchers study the behavior of a wide variety of aerosol-borne non-infectious viruses to learn how the structure of viruses affects their viability under a range of conditions in indoor and outdoor air.
The project has led to the development of research infrastructure, educational training and interdisciplinary collaboration between indoor air, microbiology, aerosol, and infectious disease experts. The team received a National Science Foundation (NSF) rapid grant and applied for a Triangle-wide NSF Engineering Research Center focused on precision microbiome engineering.
Understanding the impact of COVID-19 on behavioral, social and structural factors in South Africa: Strengthening pandemic response in low resource settings
A team at UNC-Chapel Hill, led by Audrey Pettifor, PhD, professor of epidemiology, collaborated with the South African Medical Research Council-funded Wits Rural Public Health and Health Transition Research Unit of the University of the Witwatersrand to understand the impact of COVID-19 on social determinants of health and examine access to information, prevention tools and vaccines.
Postdoctoral fellow Phindi Mashinini, PhD, from the Carolina Population Center and doctoral student Nicole Kelly from the Department of Epidemiology were a part of the study team.
The study involved two population-based surveys to assess COVID-19 prevention behaviors and impacts of COVID-19 on socio-economic and mental health outcomes in rural Mpumalanga, South Africa. The team also conducted in-depth interviews in early 2022 on prevention behaviors and vaccine uptake.
Results on vaccine hesitancy from the second survey conducted in late 2021 were published in a study titled “COVID-19 vaccine hesitancy in rural South Africa: Deepening understanding to increase uptake and access.” They showed that while vaccine uptake was high, young people were less likely to be vaccinated, and both vaccinated and unvaccinated individuals were not very confident about the safety and efficacy of the vaccine.
The team is still conducting analyses of the survey data to look at prevention behaviors, including mask use, physical distancing and handwashing, as well as the impact of COVID-19 stigma. As part of her practicum, Master of Public Health student Frantasia Hill has joined the team this summer to work on a report on key findings for local policymakers and the community.
Overall results suggest that most people had access to masks and complied often with COVID-19 prevention measures. Prevention fatigue set in as the pandemic progressed, with subjects reporting that people were less afraid and less compliant with prevention behaviors in later waves of the virus. While vaccine rates were high overall, the team identified opportunities for better vaccine communication, including the safety and efficacy of vaccines, who was eligible, and when to get vaccines during the roll out.
Contact the UNC Gillings School of Global Public Health communications team at firstname.lastname@example.org.
March 4, 2024 James Swenberg, DVM, DACVP, PhD, Kenan Distinguished Professor at the UNC Gillings School of Global Public Health in the Department of Environmental Sciences and Engineering, died October 5, 2023. There will be a Scientific Symposium to honor him and his work on March 22 from 3–5 p.m. in 133 Rosenau Hall at the Gillings School.