Investigating the Health Impacts of Environmental Chemicals
Emily Leonard '22
Biology and Public Health
Commonwealth Honors College
“Identifying modifiable risk factors to prevent disease occurrence is what I find most rewarding about doing research in the field of environmental health.”
When she was growing up in Dighton, Mass., Emily Leonard’s [‘22] father was passionate about limiting her exposure to environmental chemicals—from pesticides to cleaning products to bug spray—believing them to be potentially harmful. Leonard didn’t pay much heed to his concerns, until her studies at UMass Amherst showed her there was scientific evidence to support them.
Her “light bulb moment” came, she says, during her first-year honors course, Ideas that Change the World, when she read Dr. Tyrone Hayes’ research on the endocrine disrupting effects of the herbicide, Atrazine, which could cause complete feminization of male African clawed frogs.
“That’s when I knew I wanted to explore toxicology in the lab,” Leonard says.
For her honors thesis, Leonard has worked in the developmental toxicology lab of Alicia Timme-Laragy, associate professor of environmental health science and graduate program director, studying the effects of long-term dietary exposure to tert-butylhydroquinone (tBHQ), a synthetic food preservative. This chemical is frequently added to ultra-processed foods to extend their shelf-life and has been linked to developmental impairment, DNA damage, and carcinogenicity.
“It is essential that we determine the relationship between synthetic food preservatives and chronic disease. I hope this research can help protect marginalized communities that are often disproportionately affected by chronic disease and targeted by the ultra-processed food industry,” Leonard says.
In what Leonard believes is the first study of its kind, she and others in the lab are studying the effects of chronic tBHQ exposure on growth and organ development in zebrafish, as well as the expression of genes involved in chronic oxidative stress. The researchers are also assessing pancreas and liver development, lipid distribution, and nutrient composition in developing zebrafish larvae to investigate the adverse developmental effects of chronic dietary tBHQ exposure.
“Emily is conducting microscopy, histology, and RNA-Seq on these fish in order to better understand how this common food preservative has affected growth and development,” says Timme-Laragy. “She has had to contact core facilities, provide histology guidelines, and conduct RNA-isolation test runs, all of which she has spearheaded and moved forward.”
Through my research, I hope to draw attention to the harmful effects of such exposure and potentially enact regulatory change at the government level.
Leonard presented results of this research at the 2022 annual meeting of the Society of Toxicology, and the abstract for the project was published in The Toxicologist, the conference proceedings. She also presented preliminary findings of the meta-analysis in 2021 at the Massachusetts Undergraduate Research Conference (MassURC), co-hosted by UMass’s Commonwealth Honors College, and will again present her honors thesis at MassURC in April 2022. Leonard has been involved in other research projects at UMass as well. She conducted a year-long virtual meta-analysis of single-cell RNA-Seq data, resulting in a co-authored paper, “Relationships between type 2 diabetes, cell dysfunction, and redox signaling: A meta-analysis of single-cell gene expression of human pancreatic a- and ß-cells,” published in the Journal of Diabetes. She also works as a research assistant on the UMass Breast Health Study, a cross-sectional study assessing the association between endocrine-disrupting chemicals and breast density in young women.
Through research, Leonard has learned many practical skills, such as writing grant proposals to fund research—a crucial skill when entering graduate school and conducting individual research projects.
She hopes her research can bring about changes to improve human health.
“Most of the exposures that people face every day are non-voluntary in nature. It is almost impossible to avoid environmental chemicals, as they are found in our air, drinking water, personal care products, and diet,” she says. “Through my research, I hope to draw attention to the harmful effects of such exposure and potentially enact regulatory change at the government level. Identifying modifiable risk factors to prevent disease occurrence is what I find most rewarding about doing research in the field of environmental health.”
“I have been incredibly impressed with Emily’s can-do attitude and her ability to move things forward,” says Timme-Laragy. “Emily is academically gifted and has the grit and stamina to persist through whatever challenge she decides to tackle.”
After graduating, Leonard will pursue a PhD in environmental health at Boston University. There, she has been invited to collaborate on research investigating the associations of endocrine-disrupting chemicals on various reproductive and birth outcomes.