According to a January 2021 mapping study by the Environmental Working Group, significant levels of “forever chemicals” have been detected in 2,337 water systems in 49 U.S. states. Eguono Omagamre, an environmental toxicology doctoral student at the University of Maryland Eastern Shore, has spent the past four years studying their effect on the safety of water and agricultural food sources.
These per- and polyfluoroalkyl substances (PFAS) have been widely used in consumer products and industrial applications such as in food packaging, textile enhancements, sealants and lubricants for the past six decades. Omagamre’s interest in them was piqued because of the way they behave in the environment. Once they leach out of these materials, he said, they find their way into surface and ground water and then distribute in the environment.
“Unlike other persistent organic contaminants that accumulate in fatty tissues and matrixes, the PFAS group of chemicals prefer to partition into water,” he said. “My thinking was, if they seep and spread into water and are widely distributed in the environment, then they will readily enter into plants, and if so, what do they do once they are there.”
Omagamre said he was fortunate to have a research supervisor “who was willing to go down this rabbit hole” with him. Dr. Joseph Pitula, director of research at UMES and a professor in the Department of Natural Sciences, was onboard and reached out to his colleague, Dr. Simon Zebelo, an associate professor of entomology and plant biology in the Department of Agriculture, Food and Resource Sciences to form a team for the research.
While waiting on the delivery of soybean and tomato seedlings to begin the research, Omagamre got started with a side experiment to observe the impact of adding PFAS to the artificial diet of beet armyworm larvae.
“The result was stunning,” he said. “Some of the PFAS, particularly perfluorobutanoic acid (PFBA) influenced the development of the larvae in a “non-monotonous” manner and hastened their transition to adults about half a day faster than the controls.” The next step was cultivating soybeans and tomatoes using lab prepared irrigation water containing PFBA and feeding beet armyworm larvae with the leaves of the plants that accumulated the PFBA compounds. The results, he said, were similar to the artificial diet experiment. Further studies showed that critical physiological features of the soybean and tomato plants were modulated “non-monotonously” by different levels of PFBA in the irrigation water.
The findings from the research on the beet armyworm experiment were published in the November 2020 issue of the Archives of Environmental Contamination and Toxicology Journal. Omagamre’s poster presentation of the research, “Study of the modulatory impact of perfluorobutanoic acid (PFBA) on the growth and development of soybean (Glycine max (L.)) and cherry tomato (Solanum lycopersicum var. cerasiforme) plants,” earned first place at the 2021 Chesapeake Potomac Regional Chapter of the Society of Environmental Toxicology and Chemistry spring meeting. The chapter, which serves Maryland, D.C., Virginia and West Virginia, provides “a professional forum for individuals from private industry, academia and government agencies who are engaged in the study, analysis and solutions for environmental problems, management and regulation of natural resources, and research and development.”
The international student from Nigeria is currently probing the developmental pathways that PFBA may be modulating in the beet armyworm and the studied plants. He is investigating critical changes in the insect after exposure to dietary PFAS using biochemical and hormonal assays while also tracking genes that are turned on or off. Under the supervision of Pitula and Zebelo, he is providing guidance to two master’s students to “improve our understanding on the biochemical and molecular impacts of PFBA and other PFAS in some plant models.” Their research recently received a $600,000 Capacity Building Grant from the U.S. Department of Agriculture to investigate the level and impact of water and soil PFAS contamination in farm facilities on Delmarva.
“At the end of my research, I hope to make important contributions to understanding the implication of water and soil PFAS contamination on normal plant-insect interactions and the environment,” Omagamre said.
Gail Stephens, agricultural communications, University of Maryland Eastern Shore, School of Agricultural and Natural Sciences, gcstephens@umes.edu, 410-621-3850.
