PHHP researchers and students are collaborating to advance health on a global scale
By Katarina Fiorentino Klatzkow
Pesticides are a common protection measure to ward off crop infestation, protect homes from invasive species, and mitigate the spread of germs and bacteria. But what happens when pesticides, and other environmental toxins and chemicals, are ingested by humans in the water we drink and the food we eat? And what could the role of a commonly consumed crop, which may contain some of these pesticides, play in the health outcomes of vulnerable populations?
Tracie Baker, Ph.D., D.M.V., an associate professor in the University of Florida College of Public Health and Health Professions department of environmental and global health, and Heather Stark, M.D., M.P.H., a clinical associate professor in the department of epidemiology and program director of the Master of Science in epidemiology, recently traveled to the Oromia region of Ethiopia with student researchers from the college to help answer these questions.
In partnership with scientists from Addis Ababa University and Haramaya University, Baker’s team collected water samples to study pesticides and environmental contaminants that may be impacting human health, while Stark’s team organized focus groups and administered surveys to gain insights into the prevalence and impact of consuming a natural stimulant known as khat during pregnancy.
One of Baker’s primary research interests is transgenerational, environmentally induced disease.
In Oromia, researchers and medical professionals have noticed higher incidences of stunting, liver disease and developmental disorders, which rang alarm bells for Baker — could pesticides be a culprit?
Through funding from the UF International Center, Baker’s research aims to shed light on what pesticides are present in the region and any possible links to public and community health concerns.
“Pesticides have the tendency to bioaccumulate up the food chain, with bigger fish eating smaller fish, and then (the contaminants) making it up to large birds, mammals and people,” said Baker, a member of UF’s Emerging Pathogens Institute. “We want to get an idea of the pesticides present in this region and in what concentrations.”
In Ethiopia, pesticides such as Dichlorodiphenyltrichloroethane, more commonly known as DDT, are still used to ward off mosquitos and the spread of malaria. DDT is banned in many countries, including the United States, due to harmful effects on wildlife and ecosystems and its potential adverse human health impacts.
Studying pesticide pollution could be the key to better understanding individual, environmental and population health in the region, Baker said.
“No one has studied it yet, but in this region, it’s a very water limited area. For that reason, you have all these plants where the pesticides are basically running off into the water, which everyone is using for drinking water, to put back on crops and for livestock,” Baker said
Using the preliminary findings from the water samples collected during this trip, Baker plans to apply for a grant in collaboration with faculty from Haramaya University and Addis Ababa University.
Another ecological, and subsequent human health, concern on her radar is insect tolerance to pesticides.
“Different bugs can become tolerant to pesticides, and then you have to use other pesticides or more pesticides, either more of the chemical or additional chemicals,” said Baker. “And so you end up in this kind of loop.”
Confronting contaminants through collaboration
Mackenzie Connell, M.P.H., a Ph.D. student in public health with a concentration in environmental health, joined Baker for field sampling in Ethiopia through funding from the UF Center for African Studies.
For Connell, who is passionate about the relationship between environmental stressors and reproductive health outcomes, collaborating with Haramaya and Addis Ababa Universities to study pesticides has been one of her favorite fieldwork experiences.
“Both universities were incredibly welcoming and fantastic collaborators. I was blown away by the kindness, hospitality and accomplishments of the scientists and other folks we had the chance to meet, and I hope we are able to generate some high-quality preliminary data to share back in return (from the water samples),” she said. “It meant so much that I was invited to participate in this project. I have never done anything like it.”
Using a participatory research approach, the team found the same eagerness to collaborate among residents in Haramaya.
“In Haramaya, there was a woman who owned a well, and I personally expected some hesitation or reluctance to allow us to take some of the water to sample,” Connell said. “Water is a resource that individuals in some regions have to work much harder for access to than many environmental toxicology researchers from the U.S. are accustomed to, so this is something I wanted to be cognizant of.”
The well owner’s reaction, however, was a surprise, Connell said.
“Once we told her what it was being used for, she even had her daughters help us collect it, asked if we needed more water, and emphasized that she wants to know what is in the water they drink and sell,” said Connell. “I am grateful to have been welcomed into the community and to witness community members’ excitement and intrigue about the research we went there to conduct.”
Khat consumption and maternal health
Heather Stark brings a unique perspective to health research, with dual certifications and academic training as a medical doctor and public health practitioner. Her research focuses on nutrition and health disparities.
Stark led a research project in Harar, Ethiopia, where she was joined by Master of Public Health student, Barbara Sousa, and Bachelor of Public Health student, Melanie Moreno, through funding from the UF International Center and the UF Center for African Studies. Stark and her team collaborated with researchers and student scientists from Haramaya University to study the diet and related behaviors of pregnant women in the region, including the prevalence of consumption of khat, a green leafy shrub. In many countries, such as the United States, khat is banned due to its amphetamine-like properties. In Ethiopia, however, khat holds significant cultural importance.
“Khat use has been deeply embedded in the social and cultural framework of this community in Ethiopia for centuries and is chewed for ceremonial and religious purposes, typically on a daily basis,” said Stark. “When the khat leaves are chewed, a chemical that is similar in composition to amphetamine is released.”
But how does ingesting khat impact the health of vulnerable populations, such as pregnant mothers? Could khat consumption be related to higher incidences of certain medical conditions in Ethiopia, such as neural tube disorder in children?
Stark hopes that her research will provide possible answers to these questions.
“Chewing khat leaves while pregnant may pose additional risk to the mother and infant because it suppresses appetite and has been associated with anemia, premature birth and reduced fetal growth,” she said. “Data collected this summer indicate high rates of khat use by pregnant women in this region.”
The next step, Stark says, is following pregnant women over the course of pregnancy to study the effects of khat use on maternal and infant health outcomes.
Another area of concern, she says, is the presence of pesticides on khat. Many people consume khat unwashed to preserve freshness, which means any contaminants on the plant are then ingested.
This is where Stark’s research intersects with Baker’s.
“Khat plants are grown in this region as a cash crop. To improve yield of the khat plants, people in the region use pesticides, many of which are banned in the U.S., on the plants,” Stark said. “This is of particular concern if women are chewing the plants and ingesting the pesticides.”
Connell emphasizes the interconnectedness of public health practice and environmental monitoring when searching for solutions to pesticide pollution.
“By combining these disciplines, I have a much better understanding about why pesticides are likely being used to support the growth of a plant (khat) with immense cultural and monetary value,” said Connell. “The public health piece of this is also helpful in building rapport with collaborators because the long-term goal wouldn’t be to end pesticide use completely but to find alternatives and interventions to make the practice safer once a public health threat has been identified through this research.”
Public health in practice
Barbara Sousa, a second-year Master of Public Health student with a concentration in social and behavioral sciences, is one of the two student researchers who conducted research with Stark on khat use during pregnancy.
Sousa, who hopes to pursue a doctoral degree in public health, said participating in practical, hands-on research in Ethiopia and collaborating with community members was a transformative experience.
“The trip to Ethiopia allowed me to apply the public health knowledge I learned in the classroom in a real-world setting,” said Sousa. “I was able to learn about Ethiopian culture, apply public health concepts, and deepen my understanding of challenges faced in underserved communities.”
Her favorite aspect of the trip, she says, was engaging directly with local communities. Both Sousa and Stark emphasize the impact of their collaboration with Haramaya University on their research and experience in Ethiopia.
Fieldwork and applied research, emphasizes Sousa, is key to understanding the role of culture in health.
“The biggest lesson I took away from the trip was how interconnected cultural practices are with health behaviors,” Sousa said. “As public health researchers, we need to incorporate cultural competence when tailoring public health interventions when serving the community.”
Stark wholeheartedly agrees.
“While we were there, we also immersed ourselves in their rich cultural traditions, visited markets and schools, and attended coffee and dance ceremonies,” she said. “Experiences like these — getting to work together with people at the community level and experience their cultural traditions — gives you great respect for different cultures and values and allows you to see how they shape peoples’ behaviors, and ultimately, their health.”