Air Date: Week of March 19, 2010

Endocrine disrupting chemicals like bisphenol A have been making news lately, with several states passing regulations limiting or banning their use. The trajectory of BPA is similar to another chemical, commonly known as DES, once prescribed for pregnant and menopausal women. Host Jeff Young talks with Professor Nancy Langston about the history of endocrine disrupting chemicals and how this history can inform future chemical regulation. Her book is called, “Toxic Bodies: Hormone Disruptors and the Legacy of DES.”

Transcript

YOUNG: Concern about the plastic ingredient, bisphenol A, is shaping new laws around the country. Wisconsin banned use of BPA in children’s products and ten other states could do the same, from New Mexico to New Jersey. BPA is in a class of chemicals known as endocrine disruptors and studies link it to reproductive problems and cancer. But as states, and even some stores take action the federal Food and Drug Administration has not.

Environmental historian Nancy Langston says this all sounds very familiar. Her new book is “Toxic Bodies: Hormone Disruptors and the Legacy of DES.” DES was once prescribed for menopausal and pregnant women, and then widely used on livestock, all with disastrous effect. And professor Langston finds strong parallels between that history and the current controversy over BPA.

LANGSTON: Both BPA and DES, or diethylstilbestrol, were synthetic chemicals that during the 1930’s laboratories discovered were estrogenic. In other words, they could act like artificial estrogens and have profound effects on the body. BPA was actually going to be marketed commercially as the first synthetic estrogen until a laboratory discovered that the similar chemical, DES, was even more powerful as an estrogen.

YOUNG: Now, why did you choose to focus on DES?

LANGSTON: Nearly one tenth of American women who were pregnant during the 1950s and 1960s were treated with DES, often without their knowledge or consent. And it’s turned out to be an enormous public health disaster. DES has become one of the most powerful models for scientists to look at the effects of synthetic chemicals on the developing fetus and on the broader environment. Yet, we don’t really understand why the federal Food and Drug Administration approved the drug and why doctors marketed it so widely. And so looking a bit more clearly at the regulatory debates over DES can help us learn how to address very, very similar problems that we still face today.

YOUNG: Your book is also sort of the story of the Food and Drug Administration, FDA kind of grew up along side this chemical and DES was one of the first big challenges for this regulatory agency.

LANGSTON: Absolutely. In 1938, when the Food and Drug Administration was formed there was still an enormous public debate over what right the government had to regulate industry, and DES was the first major test case of the right and the responsibility of the federal government to regulate industry chemicals in order to protect public health.

YOUNG: And early on, sort of the father of the FDA, his whole approach was one that you might call a precautionary principle?

LANGSTON: Precisely, Harvey Washington-Wiley, and then the first commissioner of the FDA, Campbell, they called their principle the conservative principle. They did not believe that it was the consumer’s responsibility to prove that she or he had been harmed by a drug. They firmly believed that to protect the public and to protect the environment, the industry had to show that a new drug was safe.

YOUNG: And it wasn’t long before FDA drifted far away from that principle?

LANGSTON: The FDA had to decide, would this be a safe drug under the new law? The new drug director and many of his staff were enormously skeptical about giving a synthetic estrogen to women. And that was because they knew that estrogens could cause cancer. And the FDA had to negotiate this incredible uncertainty about what caused cancer and what that meant for synthetic chemicals. The chemical company started lobbying and persuaded doctors to give the drug to women for short amounts of time, and then they submitted evidence to the FDA on thousands of women who had been treated for just three weeks. They said, look, it’s safe. And many people in the FDA were very upset about this, but the political pressures on these young agencies were so powerful that the agency decided it could not defend precaution in court.

YOUNG: And then, I guess it wasn’t until early ‘70s that we really learned the full impact of those decisions?

LANGSTON: Right. In 1971, doctors began to realize that there was a formerly extremely rare form of cancer, a vaginal cancer, that was all of a sudden clustering in Boston among a group of women whose mothers had taken DES while they were pregnant. And this was revolutionary because no one really suspected that a drug could have what are called trans-generational effects. By the end of November, 1971 the warning against prescribing the drug finally came out. But it was never actually taken off the market. It was never made illegal for a doctor to prescribe DES to pregnant women.

YOUNG: And not only did we have widespread use of DES as a medicine, but far more widespread use in agriculture? How did that come about?

LANGSTON: The FDA at first, again, said no, we need to be cautious and then very quickly the regulators bent to pressures from industry and allowed it to be put on the market. At first, to turn roosters into feminized chickens that would be usable for food. And so, in 1947, many, many, many chickens began to be implanted with little pellets of DES into their necks. Almost immediately, male workers in the chicken plants began to develop symptoms, such as men began growing breasts, they began showing impotence, they began showing what the FDA called reduce virility. But the FDA at first really denied these reports and said, well, these are just farm workers, these are just workers in chemical plants, we can’t really trust them they’re not scientists. And finally, enough of these studies kept coming up that the FDA finally investigated and realized that the food itself was acting as an estrogen. And so under great pressure, the FDA removed it from chickens, but allowed it to be used in cattle. By 1954, it was approved for use in cattle and within two years some 90 percent of feedlot cattle in America were being treated with a synthetic estrogen.

YOUNG: Well, I think you’ve done a great job of showing us how FDA really fell down on the job on this, but at the same time these endocrine disrupting chemicals are a real challenge.

LANGSTON: Absolutely, because these are chemicals that have hormonal actions, it’s almost impossible to understand those effects directly. For example, we tend to think with natural poisons that a tiny dose is probably safe, whereas a big dose is going to be more toxic.

YOUNG AND LANGSTON: The dose makes the poison.

LANGSTON: Exactly! One of the founding principles in toxicology. But hormones act very differently. Just one or two tiny molecules can trigger a whole host of reactions within your body. So, quantitative risk assessment, assume that we can measure risk, that we can somehow balance the risks against the benefits. But with hormones, it’s always going to be impossible to completely know what the risks are going to be. So while quantitative risk assessment is a start, it cannot overwhelm other approaches to monitoring and measuring the risks that we face.

YOUNG: Well, you have a knack for timing because it just so happens that Congress and EPA and others are taking a new, hard look at these endocrine disruptors and considering a complete overhaul. What do you think are the lessons that we should take from the DES experience?

LANGSTON: Even very low-level residues of chemicals that have the potential to disrupt hormones can do harm to people, to animals, and to broader environments. The second lesson we should learn is that we cannot wait to regulate those chemicals until we have clear proof of experimental harm to humans. Many of the companies say, well, we haven’t proven that BPA or other endocrine disrupting chemicals definitely cause harm to a specific person. And they point out that a woman who gets cancer, she can’t prove that it was because she was exposed to a chemical, but the precautionary principle states that we should act to protect public health not by discouraging innovation, but by doing our best to ask hard questions of new drugs and new chemicals before they’re put on the market. But the lesson of DES is that we still need to protect public health even in the absence of complete certainty.

YOUNG: Nancy Langston at the University of Wisconsin. Her book is “Toxic Bodies: Hormone Disruptors and the Legacy of DES.” Thank you so much.

LANGSTON: Thank you so much. It's been a pleasure.

[MUSIC: Lester Bowie “Biggie’s Ride (Notorious Thugs) from When The Spirit Returns (Dreyfus Records 2003)]

YOUNG: In just a minute, the boys are back in town (and they’re waiting in the cattail marsh for the females to follow). The return of the red-winged blackbird. Just ahead on Living on Earth.

ANNOUNCER: Support for the environmental health desk at Living on Earth comes from The Cedar Tree Foundation. Support also comes from the Richard and Rhoda Goldman Fund for coverage of population and the environment. And from Gilman Ordway for coverage of environmental change. This is Living on Earth on PRI – Public Radio International.

 

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