Agriculture News

June 8, 2016

Purdue researchers awarded $2.5 million to study effects of perfluoroalkyl substances on amphibians

Sepulveda Marisol Sepúlveda
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WEST LAFAYETTE, Ind. - The U.S. Department of Defense has awarded a $2.5 million grant to a team of Purdue University researchers within Discovery Park’s Center for the Environment to study how amphibians are affected by perfluoroalkyl substances, chemicals used in everyday commercial products and in firefighting foams.

The Strategic Environmental Research and Development Program, a division of the Defense Department, is funding the five-year research project as part of efforts to develop an environmental risk assessment for military testing sites.

Forestry professor Marisol Sepúlveda and her co-researchers, forestry professor Jason Hoverman and agronomy professor Linda Lee, will examine the effects of exposure to perfluoroalkyl substances over the life course of three amphibian species native to Indiana: the eastern tiger salamander, northern leopard frog and American toad.

Perfluoroalkyl substances, or PFAS, are a class of chemicals that are fire-resistant and repel water, fat and other substances. They are used extensively in materials as diverse as pizza boxes and popcorn bags, nonstick cookware, carpet and water-repellant clothing. But their resistant properties also make them difficult to eliminate from the environment; they do not dissolve in water, take decades to break down and are pervasive and spread easily, having been found in environments as remote as the Arctic Circle.

In military and rescue operations, PFAS are an integral component of firefighting foams - a concern at military testing and training sites, where the foams may be used repeatedly in the same area for many years.

This research will be one of the first studies to examine the effects of PFAS on amphibians. Additional funding was awarded to groups studying birds and reptiles.

“We tried to choose three species that are representative of most of the amphibian species of North America,” said Sepúlveda. The researchers will study the effects of these chemicals throughout larval development and then the chemical uptake after metamorphosis - for example, when the tadpoles become froglets.

The chemicals are thought mainly to affect the thyroid gland, which controls rate of metabolism, growth and development. The thyroid is integral to metamorphosis in amphibians, so a chemical that affects the thyroid could cause developmental changes or delays in these animals, Sepúlveda said.

From this study, the Defense Department is mainly interested in learning what results can be expected from specific levels of exposure. Sepúlveda and her team, however, are interested in digging deeper.

“We, along with another group that we’ve worked with for many years, have applied for an additional grant to explore the physiological mechanisms behind the results that we find,” she said. “If we are awarded the grant, we can start to learn about the reasons for the effects that we see.”

While this study is focusing primarily on amphibians and their environment, other research is also being conducted on the chemicals’ effects in humans. The effects in humans are subtle, Sepúlveda said, but early research has linked PFAS exposure to high cholesterol and thyroid toxicity.

“We’re exposed to these on a daily basis,” Sepúlveda said. 

Writer: Jessica Merzdorf, 765-494-7719, 

Source: Marisol Sepúlveda, 765-496-3428,

Agricultural Communications: (765) 494-2722;
Keith Robinson,
Agriculture News Page

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