Tyrone Hayes | Frogs Are Green

Posts Tagged ‘Tyrone Hayes’

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

Wednesday, May 2nd, 2012

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.

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.

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!

Tags: american toad surveying, Amphibian research, Climate change and frogs, contaminated ground water frogs, contaminated groundwater, Dr. David Skelly, Dr. Tyrone Hayes, EDCs, effects of endocrine disrupting chemical frogs, egg cells in the gonads of male green frogs, Endocrine Disruption in Suburbia, endocrine disruptors and frogs, endocrine disruptors suburbia, endocrine-disrupting chemicals, frogs habitat loss, frogs sexual deformities, Geoffrey Giller, gray tree frog surveying, green frog hermaphrodites, hermaphrodism frogs, infectious diseases and frogs, Max Lambert, pesticide atrazine on male African clawed frogs, petridish.org, pickerel frogs, septic tanks that leach chemicals, Tyrone Hayes, USGS, water pollution endocrine disruptors, Yale’s School of Forestry and Environmental Studies
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A Field of Nightmares Updated: Atrazine, Corn, and Frogs

Wednesday, August 11th, 2010

As Susan and I are hosting family and friends, we are reposting a couple of posts this week from the past year. We’ve updated this post with new material below. This post originally ran in January 2010.

I’ve always had a sentimental attachment to cornfields—from the magical cornfield in Field of Dreams to the real cornfield across the road from a house I lived in during college years. My mother was born and raised in Iowa and I’m descended from Iowan farmers.

cornfield-medium

But chemicals, in particular Atrazine, used as herbicides on cornfields might be poisoning frogs (and people), and turning fields of dreams into fields of nightmares. These herbicides run off cornfields into streams and rivers, and leak through the water-treatment process, contaminating groundwater and drinking-water supplies.

Last summer we blogged about the problems of Atrazine. Research by University of California, Berkeley professor Dr. Tyrone Hayes, for example, has shown the effects this chemical—an endrocrine disruptor—has on frogs. It can cause birth defects and reproductive problems, including such bizarre deformities as male frogs with eggs in their testes. As reported in the Washington Post, new research at the University of Ottawa found that when exposed to Atrazine fewer tadpoles reached froglet stage. Atrazine appears to affect estrogen in humans as well and has been connected with ferility problems, cancer, and birth defects.

Warning in a Cornfield

The EPA, under the Obama administration, has launched a review of the chemical that will continue until fall 2010. It will look closely at Atrazine and other endrocrine disruptors, which might result in tighter restrictions on their use. While this sounds hopeful, Atrazine’s primary manufacturer, Syngenta, has strong ties and influence within the EPA. (Atrazine is banned in Europe, where perhaps industry and government aren’t as closely intertwined as they are in the U.S.).

For more information, please see this PDF, a report by the Land Stewardship Project and the Pesticide Action Network North America titled The Syngenta Corporation: The Cost to the Land, People, and Democracy.

Update 8/10: Save the Frogs is sponsoring the International Day of Pesticide Action, in Washington, DC, on October 24, 2010, a march through the streets of DC from the steps of the Capitol to the Environmental Protection Agency demanding a federal ban on Atrazine, the 21st Century’s DDT. Please visit the Save the Frogs site for more information and to sign a petition to get Atrazine banned. (Note: Susan designed the logo below)