Environmental historian Nancy Langston started her latest book planning to highlight the lasting legacy of manufactured chemicals that touched the lives of millions of Americans in the 1950s and 1960s.
Midway through, she realized the story she was telling was likely her own as well.
In "Toxic Bodies: Hormone Disruptors and the Legacy of DES," published March 2 by Yale University Press, Langston chronicles the history of synthetic hormone-disrupting chemicals, an industry that exploded after World War II. The result is a fascinating but horrifying account of how the vast majority of the American population became unwitting participants in a large and ultimately disastrous public health experiment.
Endocrine-disrupting chemicals encompass a range of products including synthetic hormones, polychlorinated biphenyls (PCBs), pesticides such as DDT, and plastic compounds like bisphenol A (BPA) and are nearly ubiquitous in the developed world. Exposure to these and related compounds has been linked to a rash of health problems including birth defects, reproductive problems, and several cancers.
Though some of these chemicals, such as DDT and thalidomide, have since been banned in the U.S., many others still permeate our lives. And despite their checkered history, government regulation of such toxic chemicals has been spotty and often based on faulty assumptions, argues Langston, a University of Wisconsin-Madison professor with joint appointments in the Department of Forest and Wildlife Ecology and the Nelson Institute for Environmental Studies.
Langston was inspired to explore the topic by a graduate student who grew up near the Fox River in eastern Wisconsin, a waterway lined with paper mills and so contaminated with PCBs and other industrial chemicals that it is now a Superfund site. After decades of swimming in the water and eating local fish, the woman was facing a terrible dilemma: Now knowing that her body was essentially a toxic waste site, should she breastfeed her young daughter?
"''Toxic Bodies'' explores why we have saturated the environment with so many chemicals that have the potential to change the action of hormones in our bodies," Langston says. "I start this project by asking, what happened? Why have we failed to regulate these chemicals, why have we failed to control their release into the environment, and why has so much harm come to so many?"
Perhaps, she initially thought, the lack of regulation was simply due to a lack of knowledge. But instead she found the opposite. Despite widespread scientific and anecdotal evidence that such chemicals cause cancer and a slate of reproductive problems, government regulatory agencies repeatedly approved the chemicals'' use and assured the public they were safe even into the 1970s.
For several substances, in fact, "it was the commercial potential that was a surprise, not the estrogenic and carcinogenic potential," she says.
She devotes much of her discussion to diethylstilbestrol (DES), an early synthetic estrogen created in the 1930s and one of the first such chemicals to attract widespread attention. It was initially prescribed for relieving symptoms of menopause and later marketed to pregnant women to reduce premature births and miscarriages. DES was also widely used to fatten livestock, including poultry and beef cattle.
"At one point, more than 90 percent of American cows were treated with DES, and the residues got into the meat. Pretty much everybody in America who could afford meat was exposed to the drug," Langston says.
The significance of its ubiquity was brought home to Langston halfway through writing the book, when she began having some health problems that raised concerns about possible uterine cancer and ultimately resulted in a hysterectomy.
"I started realizing that a book I thought was about other people''s experiences was also probably about my own family," she says.
Her doctors assured her that the things she was experiencing were normal, words intended to be comforting but which she found disturbing. "A lot of women in my family had cancer or infertility issues, but again doctors said that''s completely normal," Langston recalls. "Eight out of 10 women in your family having reproductive problems or cancer... You start to wonder - should that be normal?"
Given the body of information about these chemicals and their effects on animals, ecosystems and humans, she asks in "Toxic Bodies," why has the government done so little to regulate them and protect the public and environment?
It''s a story that reveals the often-conflicting demands of producers and consumers, unfounded assumptions about science and its power to assert control over nature, and the difficulty of striking a balance between precaution and progress.
DES, which ended up being a test case for government regulation, offers a bleak view. "Three times the FDA tried to say no [to approving DES], and three times they ended up reversing their decision in a matter of months," Langston says.
Each time the regulators fell back on a standard litany of arguments still used today, including the absence of definitive proof of harm, debates about the relevance of animal studies, reliance on incorrect toxicity models and assumptions, and lack of suitable detection methods.
Though DES was banned for use in livestock in 1979, its story is still playing out in the bodies, children and grandchildren of those who were exposed to the chemical. And, Langston reminds us, DES is just the tip of the synthetic iceberg. For example, the plastic BPA is also estrogenic and shows similar effects to DES in laboratory tests.
"Did we learn anything from the experience with DES?" she asks. "We''re trying. What we''ve learned is that precaution is essential for protecting public health but it''s very hard to defend in court."
She''s encouraged that the FDA recently announced that it will revisit current standards for BPA in food packaging. The move comes after several companies have voluntarily reworked products to eliminate the chemical and retailers have pulled BPA-containing products from their shelves, often in response to consumer pressure.
Above all, she hopes that the lessons of DES will not be forgotten amid the continuing onslaught of hormone disruptors that fill our lives.
"One of the things I found most striking about my own experiences is that there''s nothing striking about it," she muses about her health. "How did this become the new normal?"