Atrazine Turning Frog Princes into Frog Princesses?

Last summer, we wrote a post, Rachel Carson’s Legacy, about troubling chemicals called endrocrine disruptors, potentially harmful to both humans and frogs, that are in herbicides and pesticides, as well as in plastic, cosmetics, and many consumer products. We followed up with a post about Berkeley professor Dr. Tyrone Hayes‘ studies of one endocrine disruptor, Atrazine, a widely-used weed killer, and its effects on frogs. Some of these effects included “intersex” frogs—male frogs that developed with female characteristics.

Recently a new study by Dr. Hayes has brought increased media attention to this issue.  As reported in the article, Weed Killer Creates Mr. Moms (Science News), Atrazine was added to water in the laboratory’s frog tanks in concentrations of 2.5 parts per billion—the same amount that might be found in rivers and streams, downstream of cornfields, golf courses, or domestic lawns, where it is used as a weed killer.

Dr. Hayes and associates found that one-third of the frogs raised in the water with Atrazine behaved like females, even sending out chemicals to attract other males. Out of the  forty frogs he studied, four had high levels of estrogen, and two actually developed female reproductive organs.

The EPA has determined that up to 3 parts per billion of Atrazine are safe in U.S. waterways. But according to Dr. Hayes’s studies, that’s too much. Even minute amounts potentially harm frogs—and humans as well. Endocrine disruptors have been associated with various cancers and reproductive birth defects in boys.

Recently, sixteen cities in six Midwestern states sued the Swiss corporation Syngenta, which manufactures the chemical, for the costs of expensive water filtration systems needed to keep drinking water safe.

Scientists at Syngenta continue to assert that Atrazine is completely safe (despite the fact that it’s been banned in Europe).   When I looked up the topic on google news, I found two Syngenta-sponsored sites with names such as “Atrazine Safe to Wildlife” and “Atrazine and Frogs.” Their website denies the “baseless activist” claims.

As Randall Amster writes in his post, Silent Spring Has Sprung, on Truthout, and reprinted on the Huffington Post, these denials from Syngenta are similar to the backlash Rachel Carson received from chemical companies when she exposed the dangers of DDT in her groundbreaking 1961 book Silent Spring. He writes:

In [Silent Spring], Carson famously argued that the pesticide DDT was responsible for negative impacts on the environment, animals and humans alike, despite disinformation spread by industry and government officials about its purported safety and utility in agribusiness. Silent Spring is often credited with starting the modern environmental movement, yet today we are facing equivalent challenges and similar campaigns to conceal the potential dangers of toxic chemicals in our midst.

Below is a video from the Huffington Post Investigative Fund about atrazine:

See also the New York Times article, “Berkeley Scientist Studies Raise Corporate Hackles.”


Frog Scientist: Dr. Tyrone Hayes and Atrazine

In my post Rachel Carson’s Legacy, I wrote about widely-used chemicals called endocrine disruptors that are causing deformities in fish and frogs, and are linked to an increase in genital deformities in newborn baby boys.

When reading about endocrine disruptors, I keep coming across the work of Dr. Tyrone Hayes, a professor in the Department of Integrative Biology, at the University of California–Berkeley. He has studied the effects on frogs of an agricultural pesticide called Atrazine. Hayes found that these chemicals, even at very low levels, were causing male frogs in the wild to develop eggs in their testes (!).

I came across a lecture Dr. Hayes gave called “From ‘Silent Spring’ to Silent Night.” The lecture is about an hour long, but it’s worth watching (see below). Hayes is a funny and engaging speaker and he uses easily understood charts/graphs/pictures to explain how these chemicals effect the frogs—and how they might also effect you.

One Dr. Hayes’s experiments with frogs really hit home with me. He studied two groups of frogs that live along the same river in California. For the experiment he placed the frogs, same species, in cages in the water. One group was placed upstream of the Salinas valley, one of the largest agricultural areas of the country, which is farmed intensely all year round. Runoff containing Atrazine and other chemicals from the farms flows into the river.

The other group of frogs was placed about 50 miles downstream in a clean area. He found that the tadpoles in the area near the farms had retarded growth. They were tiny compared to the frogs in the healthier area. Hayes then injected both groups of frogs with bread yeast. The group of frogs near the farms died within a day or two after being injected with the yeast. The other frogs, from the cleaner area upstream of the agricultural area, survived. They were larger and had stronger immune systems and so were able to fight off the effects of the yeast.

I am not a scientist, but it does make me wonder about claims that some scientists make that the various viruses, parasites, and even the recent claim that frog deformities are caused by dragonfly larvae, are “part of nature.” The frogs living in the “chemical soup” obviously were smaller, weaker, and more susceptible to parasites and diseases.

As Hayes says, we can’t just pass this off as a frog problem that isn’t relevant to humans. Our hormones are chemically identical to frog hormones. Hayes discusses studies indicating higher breast cancer rates in areas where Atrazine is in the well water. He points out that the effects of the chemical may not be obvious now, but may be carried to our children, grandchildren, and even great-grandchildren.

How can you reduce your own exposure to Atrazine? If you live in the Midwest or other agricultural areas, you might consider drinking bottled water or use a Brita filter on tap water, particularly if you are pregnant. The runoff from farms is at its worst from May to August (in the Midwest). As Elizabeth Royte writes in her book Bottlemania: How Water Went on Sale and How We Buy It:

Human kidneys filter Atrazine, and most people don’t spend a lot of time swimming in herbicide-laced water as frogs do. But human fetuses do.

I was surprised to learn that Atrazine is sprayed on Christmas trees as well.

Below are two videos. The first is Hayes’s hour-long lecture “From ‘Silent Spring’ to Silent Night.” Under this video is his “Atrazine Rap,” a 2-minute summary of the lecture in case you don’t have time to watch the longer video.


Rachel Carson's Legacy

Just this past week, I re-read Rachel Carson’s groundbreaking book Silent Spring. First published in 1962, Silent Spring was a wake-up call, warning people about the devastating effects of chemical pesticides on humans and on wildlife. The book spurred changes in laws affecting our air, land, and water.


My husband reminded me that when he was a boy in the pre-Silent Spring era, he and his friends chased the “Skeeter Truck” on summer days in his suburban Philadelphia neighborhood, breathing in clouds of DDT fumes. DDT has since been banned in this country, and obviously we’ve learned a lot since then. And yet we still don’t fully understand the effects of the various chemicals that are in the products we consume, eat, drink, and use on a regular basis.

A few days ago, New York Times columnist Nicholas Kristof wrote an op-ed piece, “It’s Time to Learn from the Frogs.” After watching Hedrick Smith’s Frontline show, “Poisoned Waters,” he became concerned about chemicals called endrocrine distruptors (you can watch the show online). These chemicals—widely used in agriculture, industry, and consumer products—have been connected to increases in frog deformities and might also be connected to the rise of abnormalities in newborn boys, particularly genital deformities.

If you go to Kristof’s blog, On the Ground, you can read over 200 comments about his op-ed piece (published June 27th). One of the commenters mentioned that the Rachel Carson Homestead is sponsoring a conference on September 25, 2009, to address this issue. If you click here, you can download from their website an informative 6-page PDF about endrocrine disruptors. I admit I was surprised to learn that a type called phthalates are found in plastics used for food and drink containers, plastic wraps, soft plastic children’s toys, shampoos, shower curtains, and nail polish—to name just to name a few. One would have to live in a plastic bubble to avoid them (or rather an organic non-plastic bubble). In a another post, I will explore the ways in which we can avoid at least some of these chemicals.

Carson’s legacy continues….

UPDATE:  A couple of days after I wrote this, I found out that Stephen Colbert interviewed Nicholas Kristof about this subject on June 27th. Here’s a link to the Colbert Nation where you can watch the episode.  I’m a big fan of Stephen Colbert. Here’s a fun fact you might not know: he once wanted to be a marine biologist.