Archive for the ‘Our Stolen Future’ Category

“Our Stolen Future,” by Theo Colborn, Dianne Dumanoski, and John Peterson Myers.
Hand-Me-Down Poisons Excerpt

Gilbertson had given Colborn complete access to his meticulously organized collection of material on each animal species that breeds in the Great Lakes basin–data that he had gathered over the years and arranged in chronological order in three-ring binders. Colborn was awed by the elegance of the effort and by the years of dedication and scholarly consideration that it reflected. With a sense of history, Gilbertson had gone to great lengths to collect papers and studies dating back a half century or more–literature documenting that the problems seen today in the birds and wildlife along the lakes had not been reported before World War II. In the bald eagle file, she found evidence of parallel declines in the postwar period in the bald eagle in North America and in its European cousin, the white-tailed sea eagle, along with a collection of reports detailing the concentrations of synthetic chemical contaminants found in both species. Photocopies from Gilbertson’s archive had greatly enriched Colborn’s files, but their conversations, during which Gilbertson generously shared his broad experience, had proven even more valuable.

Over lunch in the Canadian Wildlife Service cafeteria, Colborn, Gilbertson, and Fox had discussed the wildlife evidence contradicting the frequent claims that the lakes had been cleaned up. The two Canadians shared the conviction the wildlife work had likely implications for human health and constituted a warning humans ought to heed. In her survey of the scientific literature, Colborn had been fascinated by some of Fox’s work, which reported evidence of behavioral changes in wildlife as well as signs of physical damage.

In herring gull colonies, particularly in highly polluted areas of Lakes Ontario and Michigan, Fox and his colleagues had found nests with twice the normal number of eggs–a sign that the birds occupying the nests were two females instead of the expected male-female pair. The phenomenon, which persisted in some areas, had been particularly prevalent in the mid to late 1970s. During this period, Fox had collected and preserved seventeen near-term embryos and newly hatched chicks from the affected colonies in hopes that he might eventually discover what was causing this unusual behavior and other reproduction problems.

A few years later, Fox encountered a scientist who might help him find the answer. Michael Fry, a wildlife toxicologist at the University of California at Davis, had investigated how the pesticide DDT and other synthetic chemicals disrupt the sexual development of birds after hearing reports of nests with female pairs in western gull colonies in southern California. While some looked for an evolutionary explanation for the phenomenon, Fry had suspected contamination. Reports in scientific literature indicated that a number of synthetic chemicals, including the pesticide DDT, could somehow act like the female hormone estrogen.

To test his theory, Fry had injected eggs taken from western gull and California gull colonies in relatively uncontaminated areas with four substances–two forms of DDT; DDE, the breakdown product of DDT; and methoxychlor, another synthetic pesticide that had also been reported to act like the hormone estrogen. The experiment showed that the levels of DDT reported in contaminated areas would disrupt the sexual development of male birds. Fry noted a feminization of the males’ reproductive tracts, evident by the presence of typically female cell types in the testicles or, in cases of higher doses, by the presence of an oviduct, the egg-laying canal normally found in females. Despite all this internal disruption, the chicks had no visible defects and looked completely normal.

As soon as he could make arrangements, Fox shipped the preserved embryos and chicks off to Fry in California. In his examination of the birds’ reproductive tracts, Fry found that five of the seven males were significantly feminized and two had visibly abnormal sex organs. Five of the nine females showed significant signs of disrupted development as well, including the presence of two egg-laying canals instead of the one that is normal in gulls. Such disruption, Fry noted, could indicate that the birds had been exposed to chemicals that acted like the female hormone estrogen.

Earlier experiments by other researchers had shown that exposing male birds to estrogen during development affects the brain as well as the reproductive tract and permanently suppresses sexual behavior. When chicken and Japanese quail eggs received estrogen injections, the males that hatched never crowed, strutted, or exhibited mating behavior as adults.

Taken together, the evidence in the Great Lakes suggested that the females were nesting together because of a shortage of males, which might be absent because they were disinterested in mating or incapable of reproducing. Though most eggs in these same sex nests were infertile, these females sometimes managed to mate with an already paired male and hatch a chick. The female pairs appeared to be an effort to make the best of a bad situation.

Fox and others had noticed other behavioral abnormalities as well, particularly in birds that had high levels of chemical contamination. In Lake Ontario colonies, the birds showed aberrant parental behavior, including less inclination to defend their nests or sit on their eggs. In unsuccessful nests, the incubating eggs were unattended for three times as long as in the nests where birds successfully produced offspring. A study comparing reproduction in Forster’s terns nesting in clean and contaminated areas reported that nest abandonment and egg disappearance, often due to theft by predators, was substantial in the contaminated area on Lake Michigan but virtually nonexistent in the clean colony on a smaller lake in Wisconsin. Parental inattentiveness clearly diminished the chances that the eggs would hatch and the chicks would survive.

What Colborn remembered afterward about the conversation was how cautious they had all been. Despite the shared view that wildlife findings had implications for humans, no one wanted to acknowledge the unspoken question hanging in the air. No one dared ask whether synthetic chemicals might be having similar disrupting effects on human behavior. Those were treacherous waters they all preferred to avoid.

pages 20 – 22

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p-Nonyl-phenol: an estrogenic xenobiotic released from “modified” polystyrene by A M Soto, H Justicia, J W Wray, and C Sonnenschein – 1991

This significant discovery was documented in the book Our Stolen Future.

Somehow the plate didn’t look right, so Sonnenschein adjusted the microscope and looked again. His eyes were not playing tricks. The whole plate–every single colony growing in a specially modified blood serum–was as crowded as a subway train at rush hour. Regardless of whether they added estrogen or not, the breast cancer cells had been multiplying like crazy.

In all their years of cell work, they had never seen anything like it. At first, they felt stunned. They didn’t know what to think except that something had gone seriously wrong.

They carefully prepared another batch of plates with breast cancer cells, and once again, the breast cancer cells began mulitplying like crazy. It wasn’t a fleeting event. The mysterious contamination was still somewhere in the lab. They considered every possible explanation from carelessness to sabotage. In the end, the cause proved beyond their wildest imaginings, something even stranger and more unsettling than human sabotage.

When they stored the hormone-free blood serum in some of the test tubes, their breast cancer cells showed an estrogenlike response and multiplied like mad. But the cells showed no response to serum stored in other identical-looking tubes. Although the medical school lab kept ordering the tube number they had used for years, Corning was now supplying a lab tube that had a different chemical composition. When Soto asked about the chemical content of the new resin, Corning declined to disclose the information on the grounds that it was a “trade secret.”

It took months to purify the compound in the plastic that caused an estrogenlike effect in their experiments and do a preliminary identification using mass spectrometry analysis. Finally, they were ready to send a sample of the substance across the river to chemists at MIT for final identification.

At the end of 1989–two years after their detective work had started – they had a definitive answer: p-nonylphenol. Manufacturers add nonylphenols to polystyrene and polyvinyle chloride, known commonly as PVC, as an antioxidant to make plastics more stable and less breakable.

Soto & Sonnenschein found many concerning studies. One found that the food processing and packaging industry used PVCs that contained alkylphenols. Another reported finding nonylphenol contamination in water that passed through PVC tubing. They even discovered that nonylphenol is used to synthesize a compound in contraceptive creams. They also learned that the breakdown of chemicals found in industrial detergents, pesticides, and personal care products can likewise give rise to nonylphenol.

450 million pounds in 1990 in the United States alone and 600 million pounds globally.

Alkylphenol polyethoxylates have been widely used since the 1940s, but in the past decade they have come under increasing scrutiny because of their toxicity to aquatic life, particularly as they break down. By the late 1980s, several European countries had already banned the use of household cleaners of nonylphenol ethoxylates, the compound in this group most commonly used in cleaning products, and similar restrictions are under consideration in their countries as well. While many still allow their use, however, in cleaners prepared for industrial purposes, fourteen European and Scandinavian countries agreed in 1992 to phase out this use by 2000.

Our Stolen Future

p-Nonyl-phenol: an estrogenic xenobiotic released from “modified” polystyrene.

A M Soto, H Justicia, J W Wray, and C Sonnenschein

Environ Health Perspect. 1991 May; 92: 167–173.

Department of Anatomy and Cellular Biology, Tufts University Health Sciences Schools, Boston, MA 02111.


Alkylphenols are widely used as plastic additives and surfactants. We report the identification of an alkylphenol, nonylphenol, as an estrogenic substance released from plastic centrifuge tubes. This compound was extracted with methanol, purified by flash chromatography and reverse-phase high performance liquid chromatography, and identified by gas chromatography-mass spectrometry. Nonylphenol induced both cell proliferation and progesterone receptor in human estrogen-sensitive MCF7 breast tumor cells. Nonylphenol also triggered mitotic activity in rat endometrium; this result confirms the reliability of the MCF7 cell proliferation bioassay. The estrogenic properties of alkylphenols, specifically nonylphenols, indicate that the use of plasticware containing these chemicals in experimental and diagnostic tests may lead to spurious results, and these compounds as well as alkylphenol polyethoxylates may also be potentially harmful to exposed humans and the environment at large.

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This significant discovery is mentioned in Our Stolen Future.

Researchers soon realized the estrogenic effect was due to a contaminant rather than a hormone that was causing the breast cancer cells to rapidly multiply. They determined that the contaminant was bisphenol-A – BPA and that the source of the contamination was the polycarbonate lab flasks used to sterilize the water used in the experiments….

In a 1993 paper, the Stanford team reported their discovery and their discussions with the manufacturer of polycarbonate, GE Plastics Company. Apparently aware that polycarbonate will leach, particularly if exposed to high temperatures and caustic cleaners, the company had developed a special washing regimen that they thought had eliminated the problem.

In working with the company, however, the researchers discovered that GE could not detect bisphenol-A in samples sent by the Stanford lab-samples that were causing proliferation in estrogen-responsive breast cancer cells. The problem proved to be the detection limit in GE’s chemical assay-a limit of ten parts per billion. The Stanford team found that two to five parts per billion of bisphenol-A was enough to prompt an estrogenic response in cells in the lab. pages 130 – 131

Bisphenol-A: an estrogenic substance is released from polycarbonate flasks during autoclaving.

AV Krishnan, P Stathis, SF Permuth, L Tokes and D Feldman
Division of Endocrinology, Stanford University School of Medicine, California 94305

Endocrinology, Vol 132, 2279-2286

In studies to determine whether Saccharomyces cerevisiae produced estrogens, the organism was grown in culture media prepared using distilled water autoclaved in polycarbonate flasks. The yeast- conditioned media showed the presence of a substance that competed with [3H]estradiol for binding to estrogen receptors (ER) from rat uterus. However, it soon became clear that the estrogenic substance in the conditioned media was not a product of the yeast grown in culture, but was leached out of the polycarbonate flasks during the autoclaving procedure. [3H]Estradiol displacement activity was monitored by ER RRA, and the active substance was purified from autoclaved medium using a series of HPLC steps. The final purified product was identified as bisphenol-A (BPA) by nuclear magnetic resonance spectroscopy and mass spectrometry. BPA could also be identified in distilled water autoclaved in polycarbonate flasks without the requirement of either the organism or the constituents of the culture medium. Authentic BPA was active in competitive RRAs, demonstrating an affinity approximately 1:2000 that of estradiol for ER. In functional assays, BPA (10-25 nM) induced progesterone receptors in cultured human mammary cancer cells (MCF-7) at a potency of approximately 1:5000 compared to that of estradiol. The BPA effect on PR induction was blocked by tamoxifen. In addition, BPA (25 nM) increased the rate of proliferation of MCF-7 cells assessed by [3H]thymidine incorporation. Thus, BPA exhibited estrogenic activity by both RRA and two functional bioresponse assays. Finally, MCF-7 cells grown in media prepared with water autoclaved in polycarbonate exhibited higher progesterone receptor levels than cells.grown in media prepared with water autoclaved in glass, suggesting an estrogenic effect of the water autoclaved in polycarbonate. Our findings raise the possibility that unsuspected estrogenic activity in the form of BPA may have an impact on experiments employing media autoclaved in polycarbonate flasks. It remains to be determined whether BPA derived from consumer products manufactured from polycarbonate could significantly contribute to the pool of estrogenic substances in the environment.

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