Toenails and saliva: Researching arsenic poisoning in Thailand
Written by Laurel Thomas Gnagey
She faced monsoon rains and dodged lunging dogs. She got lost on winding dirt roads on long days when she might only see five people. Still, Kate Helmick just can’t say enough about the summer she spent gathering toenail and saliva samples in southern Thailand for a study about chronic arsenic poisoning.
“Even though I was doing the same thing every day, the days were not the same,” said Helmick, a master’s student in the School of Public Health at the University of Michigan. “I wasn’t sure how the people would respond to me but everyone was excited to meet me and very friendly. Some were really touched that someone from a different country would come to research them.”
Helmick was working with a doctoral student from Prince of Songkla University through a connection with SPH faculty member Dr. Laura Rozek, assistant professor of Environmental Health Sciences.
Chronic exposure to arsenic affects about 200 million people worldwide, Helmick said. The cases in Thailand are due to the aftermath of tin mining operations that contaminated ground water.
Toenails and saliva are the easiest samples to collect in an area where it would be difficult to keep blood and other biomaterials at the proper temperature.
Helmick not only gathered the samples for lab analysis, she checked people for skin lesions – possible precursors to skin cancer, such as Bowen’s disease, basal and squamous cell carcinomas.
Out of the 250 people examined, 125 had suspected lesions, which would later be examined and verified by a dermatologist.
Since returning to U-M, Helmick has been working in Rozek’s lab to further analyze the saliva samples to see how arsenic affects DNA methylation, a normal biological process that moderates or inhibits gene expression. It’s part of a study called epigenetics, which looks at how environmental factors, such as heavy metal exposure, influence human genetics.
“Little is understood about the role arsenic and epigenetics play in how the lesions are formed,” she said, “so we’re seeing if people with more skin lesions have more epigenetic changes.”
Helmick said the project convinced her that global environmental health was a good career fit.
“Doing research in a developing country is so different than doing it here,” she said. “I was embedded in this community, which was an awesome experience.”
The student added, “As a tall, pale, blonde woman, I stuck out a lot. But their culture is just so welcoming and friendly. They invited us in, gave us food picked from their gardens and told us stories.”
(This story was first published by Michigan’s World Class, which shares stories about innovative teaching and learning at U-M.)