Chemical Pollution in Your Backyard: Researching the Effects of Endocrine Disruptors in Suburbia

We were so pleased to receive this guest post by Geoffrey Giller, who is a Master’s of Environmental Science candidate, 2013, at the Yale School of Forestry and Environmental Sciences. At Frogs Are Green, we have explored the issue of endocrine disruptors and their possible effects on frogs, as well as on humans. We look forward to learning the results of his research.

Geoffrey Giller environmental sciences Yale school

Geoff Giller readying nets for sampling at a golf course (Photo credit: Susan Bolden)

Frogs are threatened globally by a host of stressors, from habitat loss to climate change to infectious diseases. One threat receiving increased scientific attention is endocrine-disrupting chemicals (EDCs). These chemicals interfere with normal hormonal function. In 2002, Dr. Tyrone Hayes published a paper in Nature detailing the feminizing effects of the widely-used pesticide atrazine on male African clawed frogs. Since then, there has been increasing research showing similar effects of other EDCs on frogs and fish. There is also more and more evidence that endocrine disruptors are widely prevalent pollutants in the water bodies of the United States.

As a Master’s student at Yale’s School of Forestry and Environmental Studies, I want to further investigate the presence and effects of these EDCs. My advisor, Dr. David Skelly, recently published a paper showing that green frog hermaphrodites are most prevalent in suburban areas. While most research since Dr. Hayes’ paper has focused on agricultural areas, Dr. Skelly’s work indicated that there may be a significant source of EDCs causing these high rates of hermaphroditism (as demonstrated by the presence of egg cells in the gonads of male green frogs) in suburban areas.

photomicrographic frog cells

Testicular oocytes (egg cells in male gonads) from Skelly et al. 2010

This topic has implications both for frog conservation, as such sexual deformities likely inhibit frogs’ abilities to reproduce, and for human health, since suburban areas are much more densely populated than agricultural ones. But while the presence of these deformities has been confirmed, their cause has not. Dr. Skelly has hypothesized that the cause may be certain EDCs called synthetic estrogenic compounds; these chemicals are found in medications such as birth control pills as well as in some cosmetic products. The source of these chemicals would likely be septic tanks that leach chemicals into the groundwater; this contaminated groundwater then flows into nearby ponds, streams, and wetlands where frogs breed and live.

I am working with my fellow Master’s student, Max Lambert, to identify exactly what chemicals are present in the groundwater and pond water in suburban areas and what effect these chemicals are having on frogs. In collaboration with scientists at USGS, we will be installing sampling devices at 9 suburban sites, as well as three agricultural and three forested sites as comparisons. We will sample the groundwater and the pond water for a large range of chemicals including medications, synthetic estrogens, pesticides, and a host of other man-made compounds. This study will provide a list of the chemicals that may be responsible for the deformities in the frogs that we are observing.

Small Frog size of fingernail

Max Lambert with a peeper (Photo credit: Hannah Erin Bement)

In addition to the water testing, we will be surveying three types of frogs—American toads, gray tree frogs, and pickerel frogs—for similar sexual deformities. By combining the data from our water testing with the rates of deformities in frogs at these same ponds, we will be able to say which chemicals are likely causing deformities, and which are not. This information will be crucial for the future regulation of these chemicals.

The main stumbling block of this project is the cost. EDCs can have significant biological effects when present at very low concentrations; however, doing water testing for such low concentrations of chemicals requires highly specialized equipment. While some of our costs are covered by our collaboration with USGS, we still need to raise some funds. For more information on our project, and for a chance to help us out with this research, please go here: http://www.petridish.org/projects/estrogens-in-your-backyard-the-chemical-ecology-of-suburbia. This website allows researchers to raise necessary resources through “crowdfunding,” or multiple small donations from a large number of people. We are close to our target funding amount, but could use a little more help. Take a look at our page (as well as the various rewards for different donation amounts), and we would be incredibly grateful for your support!


Today is Save the Frogs Day!

Today is Save the Frogs Day, organized and created by conservation biologist Dr. Kerry Kriger. Tune in to hear an interview today with Dr. Kriger at 4:30 US Eastern or 1:30 PST (Sirius 112/XM 157) on Martha Stewart Living Radio.

As it’s been almost a year since we began the Frogs Are Green blog, we thought we’d share some thoughts about it with you. At first when we told our friends and family we were starting a blog to increase awareness about the global amphibian decline, they were a bit mystified, even amused. But I’m happy to say that a year later, almost all have become enthusiastic supporters. So we’d like to give you a few “talking points” in case you come across people who say with skepticism—frogs needs saving? Huh?

Frogs, of course, are not the only animals that need help, and we are personally involved with efforts to save other animals, particularly marine animals. But amphibians as a class of animals are threatened with extinction. That’s like saying that all mammals might soon be extinct. This is the largest mass extinction since the dinosaurs. Frogs have survived for 360 million years (and were on Earth long before the dinosaurs) and yet one-third or more of frog species are in danger of extinction.

Frogs are bioindicators—they reflect back to us the environmental health of our planet. Their permeable skin makes them especially vulnerable to environmental contaminants, such as agricultural, industrial, and pharmaceutical chemicals, particularly endocrine disruptors.  Frogs are manifesting reproductive deformities and hormonal disorders, possibly as a result of the stew of chemicals in the water in which they live. As endocrine distruptors are in the water we drink and are in dozens of consumer products we use everyday, we have reason to be concerned. Some scientists believe that an increase in the incidence of newborn baby boys born with genital deformities might be due to endocrine disruptors they have absorbed in utero.

Biodiversity is of critical importance to all of us—scientists still don’t fully understand how all elements interact in an ecosystem, but we do know that disasters occur when we alter even one small part of it (by introducing nonnative species etc). Frogs form an important part of ecosystems as both predator and prey.

While there is no cure yet for the chytrid fungus devastating frog populations, it should make us pause to consider that a whole class of animals could be wiped out by a worldwide fungus. Why aren’t frogs able to fight this off this infection? What are the underlying causes of the fungus? There are so many questions that need answers.

Frogs are subject to all the usual environmental woes—habitat loss, pollution, global warming, overcollection, invasive species. By helping frogs, we help other animals that might not have such a high profile (although frogs have a pretty low profile, all things considered). By focusing on the rainforest frogs, for example, we also help preserve the rainforest and its animals.

Frogs are part of our cultural heritage—our folktales, fairy tales, myths, children’s stories, and legends. In many cultures, they are a symbol of good luck, fertility, healing, prosperity, and are associated with rain and good harvests. And don’t forget our friends Kermit, and Frog and Toad, and Mr. Toad.

The amphibian decline is an environmental issue that you can do something about, possibly in your own backyard or neighborhood. We recently received a comment from a man in Georgia who decided not to fill in a pond on his property because he noticed that several frog species live in the pond. Another commenter from Pennsylvania has asked how he can create a frog pond in his backyard. You can lend your voice to land conservation efforts that protect vernal pools, for example.

Rachel Carson warned in her 1961 book Silent Spring about a world without birds. Can you imagine a world without frogs? Frogs, after all, are the Earth’s most ancient singers. We want to continue to hear their choruses for a long, long time.

So as you enjoy Save the Frogs day, listen to some frog songs. And please join us in helping to save frogs. We’d love to hear from you.