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.