Each night at dinnertime, a familiar ritual played out in Michael Green's home: He'd slide a stainless steel sippy cup across the table to his two-year-old daughter, Juliette, and she'd howl for the pink plastic one. Often, Green gave in. But he had a nagging feeling. As an environmental-health advocate, he had fought to rid sippy cups and baby bottles of the common plastic additive bisphenol A (BPA), which mimics the hormone estrogen and has been linked to a long list of serious health problems. Juliette's sippy cup was made from a new generation of BPA-free plastics, but Green, who runs the Oakland, California-based Center for Environmental Health, had come across research suggesting some of these contained synthetic estrogens, too.
He pondered these findings as the center prepared for its anniversary celebration in October 2011. That evening, Green, a slight man with scruffy blond hair and pale-blue eyes, took the stage and set Juliette's sippy cups on the podium. He recounted their nightly standoffs. "When she wins…every time I worry about what are the health impacts of the chemicals leaching out of that sippy cup," he said, before listing some of the problems linked to those chemicals—cancer, diabetes, obesity. To help solve the riddle, he said, his organization planned to test BPA-free sippy cups for estrogenlike chemicals.
The center shipped Juliette's plastic cup, along with 17 others purchased from Target, Walmart, and Babies R Us, to CertiChem, a lab in Austin, Texas. More than a quarter—including Juliette's—came back positive for estrogenic activity. These results mirrored the lab's findings in its broader National Institutes of Health-funded research on BPA-free plastics. CertiChem and its founder, George Bittner, who is also a professor of neurobiology at the University of Texas-Austin, had recently coauthored a paper in the NIH journal Environmental Health Perspectives. It reported that "almost all" commercially available plastics that were tested leached synthetic estrogens—even when they weren't exposed to conditions known to unlock potentially harmful chemicals, such as the heat of a microwave, the steam of a dishwasher, or the sun's ultraviolet rays. According to Bittner's research, some BPA-free products actually released synthetic estrogens that were more potent than BPA.
Estrogen plays a key role in everything from bone growth to ovulation to heart function. Too much or too little, particularly in utero or during early childhood, can alter brain and organ development, leading to disease later in life. Elevated estrogen levels generally increase a woman's risk of breast cancer.
Estrogenic chemicals found in many common products have been linked to a litany of problems in humans and animals. According to one study, the pesticide atrazine can turn male frogs female. DES, which was once prescribed to prevent miscarriages, caused obesity, rare vaginal tumors, infertility, and testicular growths among those exposed in utero. Scientists have tied BPA to ailments including asthma, cancer, infertility, low sperm count, genital deformity, heart disease, liver problems, and ADHD. "Pick a disease, literally pick a disease," says Frederick vom Saal, a biology professor at the University of Missouri-Columbia who studies BPA.
BPA exploded into the headlines in 2008, when stories about "toxic baby bottles" and "poison" packaging became ubiquitous. Good Morning America issued a "consumer alert." The New York Times urged Congress to ban BPA in baby products. Sen. Dianne Feinstein (D-Calif.) warned in the Huffington Post that "millions of infants are exposed to dangerous chemicals hiding in plain view." Concerned parents purged their pantries of plastic containers, and retailers such as Walmart and Babies R Us started pulling bottles and sippy cups from shelves. Bills banning BPA in infant care items began to crop up in states around the country.
Today many plastic products, from sippy cups and blenders to Tupperware containers, are marketed as BPA-free. But Bittner's findings—some of which have been confirmed by other scientists—suggest that many of these alternatives share the qualities that make BPA so potentially harmful.

The center shipped Juliette's plastic cup, along with 17 others purchased from Target, Walmart, and Babies R Us, to CertiChem, a lab in Austin, Texas. More than a quarter—including Juliette's—came back positive for estrogenic activity. These results mirrored the lab's findings in its broader National Institutes of Health-funded research on BPA-free plastics. CertiChem and its founder, George Bittner, who is also a professor of neurobiology at the University of Texas-Austin, had recently coauthored a paper in the NIH journal Environmental Health Perspectives. It reported that "almost all" commercially available plastics that were tested leached synthetic estrogens—even when they weren't exposed to conditions known to unlock potentially harmful chemicals, such as the heat of a microwave, the steam of a dishwasher, or the sun's ultraviolet rays. According to Bittner's research, some BPA-free products actually released synthetic estrogens that were more potent than BPA.
Estrogen plays a key role in everything from bone growth to ovulation to heart function. Too much or too little, particularly in utero or during early childhood, can alter brain and organ development, leading to disease later in life. Elevated estrogen levels generally increase a woman's risk of breast cancer.
Estrogenic chemicals found in many common products have been linked to a litany of problems in humans and animals. According to one study, the pesticide atrazine can turn male frogs female. DES, which was once prescribed to prevent miscarriages, caused obesity, rare vaginal tumors, infertility, and testicular growths among those exposed in utero. Scientists have tied BPA to ailments including asthma, cancer, infertility, low sperm count, genital deformity, heart disease, liver problems, and ADHD. "Pick a disease, literally pick a disease," says Frederick vom Saal, a biology professor at the University of Missouri-Columbia who studies BPA.
BPA exploded into the headlines in 2008, when stories about "toxic baby bottles" and "poison" packaging became ubiquitous. Good Morning America issued a "consumer alert." The New York Times urged Congress to ban BPA in baby products. Sen. Dianne Feinstein (D-Calif.) warned in the Huffington Post that "millions of infants are exposed to dangerous chemicals hiding in plain view." Concerned parents purged their pantries of plastic containers, and retailers such as Walmart and Babies R Us started pulling bottles and sippy cups from shelves. Bills banning BPA in infant care items began to crop up in states around the country.
Today many plastic products, from sippy cups and blenders to Tupperware containers, are marketed as BPA-free. But Bittner's findings—some of which have been confirmed by other scientists—suggest that many of these alternatives share the qualities that make BPA so potentially harmful.
by Mariah Blake, Mother Jones | Read more:
Image: Evan Kafka