Our Stolen Future:
Effects of Biologically Active Plastics
A Book Review 
By Michael P. Milburn, PhD

UPdate Spring 1996

     Rachel Carson was an American scientist with a reputation for careful and meticulous work.  She was also an award winning writer known for elegant and insightful prose.  Her 1962 book Silent Spring warned of the dangers of chemical pesticides.  Silent Spring set out some deeply disturbing issues in a way that touched off a world wide environmental movement.
     Working several decades after Silent Spring, in the shadow of Rachel Carson, Theo Colborn is creating her own legacy.  It was not until after the age of fifty that Colborn returned to school, pursuing a PhD.  A nature lover, Colborn fulfilled, at age 58, a life-long dream of getting a degree in ecology.  Colborn then became involved in a project looking at the health of the Great Lakes, those great cesspools of modern civilization.
     While the condition of the Lakes had improved (or at least stabilized), due to the “greening” of government and industry, Colborn sensed that things were still not what they should be.  Much of the scientific (and public) interest in toxics had revolved around the question of cancer.  No doubt this was (and is) important work, but it has also served as a blind to the possibility of other concerns.  Colborn almost fell into this trap.
     Yet Colborn began to see links between the research work of various scientists investigating the biological effects of chemicals.  She found that animals highest on the food chain were having the biggest problems, especially with reproduction and development.  She began to wonder if many of these chemicals were actually interfering with hormonal systems, disrupting vital regulatory processes and causing a host of illnesses.  Colborn’s book, Our Stolen Future, written with Pete Myers and Dianne Dumanoski, gives an overview of the potential problem.
     A pre-publication excerpt from the book published in the March, 1996 issue of Natural History magazine (upon which this article is based) describes the book as follows: “[The authors] have found that hormone-disrupting chemicals are ubiquitous and that the pathologies they cause may result even from extremely low levels of exposure.  Although many synthetic chemicals have been tested for carcinogenic effects, few have been scrutinized for their impact on the human endocrine system.  As the authors of Our Stolen Future observe, if such substances are causing wide-scale disruption of the hormones that enable us to grow and reproduce, we may be witnessing an evolutionary tragedy in the making.”
     What we are talking about here is various human-made chemicals, many of them widely dispersed throughout the environment, getting into animals and people, gumming up the works and causing a whole host of problems.  Scientists have looked at problems from thyroid disruption, fertility changes, birth deformities, and weakened immune systems.  In my opinion, since the Colborn hypothesis envisions a disruption of organization and regulation, not specific diseases, this may be the seed of understanding a wide range of systemic health problems that remain enigmatic.  
     Our Stolen Future profiles decades of research.  Bald eagles in Florida were found to be sterile in the 1940s.  Britain’s otters began to disappear in the 1950s: Research pointed to a synthetic chemical cause.  Mink raised in farms around the Great Lakes were fed fish, and began to suffer dramatic reproductive problems: studies linked the problem to PCBs.  In the 1970s, Californian gulls experienced a shortage of males: researchers wondered if pesticides were feminizing male embryos.  In the 1980s, 60 percent of alligators in one Florida lake had abnormally small penises.  And this decade, researchers have begun to focus on human reproductive problems, pointing to a decline in male fertility.
     The Colborn hypothesis works like this.  Hormones are chemicals produced in the body, used to regulate and control physiological processes.  Hormones travel to parts of the body where they are to do their work.  Cells have molecules called receptors that can link with these hormones, in a sort of lock and key interaction.  When a receptor links with a hormone, changes are produced in the cell.  It is like a key turning on the ignition.
     The problem seems to be that various synthetic chemicals can mimic a hormone’s ability to link with a receptor.  While the concentration of hormones is very precisely controlled by the body, these unnatural molecules are not subject to the normal control of hormones.  Thus these molecules can produce disruptive and dangerous effects.  Over fifty hormone-mimicking chemicals have been identified by scientists to date; some mimic estrogen, an important well-known regulating chemical, others can conflict with thyroid and testosterone processes.  There is evidence such hormone-mimicking chemicals have “major cumulative effects” at “seemingly insignificant quantities” and can work synergetically to produce effects not seen individually.
     Serendipity has played an important role in many discoveries about hormone-mimics.  A team at Tufts Medical School in Boston, for example, was looking at laboratory colonies of human breast cancer cells that multiply under the influence of estrogen.  They were trying to find what caused the cells to stop growing when estrogen was removed.  One day things went horribly wrong with their experiment.  All the cells, even the ones without estrogen, were growing like crazy.  Contamination was suspected.
     It took the scientists months to trace the source of contamination to a plastic tube used in the course of preparing the cell cultures.  A chemical called pnonylphenol – a type of chemical put in plastics like polystyrene and PVCs to make them sturdier – was the problem.  It had been added to the plastic in the tube recently by the manufacturer (Corning) who had not indicated any such change in their catalog.  They found that PVC type plastics containing these hormone-mimicking chemicals were widely used in food processing and packaging, and even as water piping.  They showed that hormone-mimicking effects like the ones they observed in cell colonies grown in the lab could also occur in rats.
     The story doesn’t end there.  Chemicals able to break down into the type of estrogen-mimicking compound that ruined the Tufts experiments by causing wild growth of breast cancer cells in the laboratory could also be found in many detergents and personal-care products.  These alkylphenol polyethoxylates were used since the 1940s, but banned in Europe in the late 1980s because they were toxic to aquatic ecosystems.  The United States was still consuming a whopping 450 million pounds a year in 1990!!  As Our Stolen Future points out, here was a potential danger where you would least expect it: in products usually considered benign and inert and found in everyone’s kitchens and bathrooms.  
     A laboratory in Stanford University, around the same time, also found an estrogen-mimicking chemical, this time in an entirely different type of plastic, polycarbonate, used not only to produce lab flasks, but the large plastic bottles used for drinking water!! In meeting with GE Plastics Company, the plastic maker, the Stanford scientists learned that this hormone-mimic, bisphenol-A, was known to leach out from the plastic, and the company had tried to develop a procedure to deal with this problem.  Yet, the company’s equipment could not measure bisphenol-A at levels below 10 ppb, while only 2-5 ppb was able to cause effects in the laboratory cells at Stanford.
     After hearing of reports of these “biologically active plastics”, a group of researchers in Spain looked at the plastic coatings in food cans, used to avoid metal contamination.  Such coatings are used in most canned food in the United States (and, I presume, Canada).  They found the same chemical that had affected experiments in the Stanford lab in “stunningly high concentrations” in corn, peas and artichokes, and all told, in 50 % of the canned foods they studied.  Some cans contained as much as 27 times the amount needed to make breast cancer cells grow in the laboratory.
     Our Stolen Future asks whether we have been suffering from 50 years of exposure to these importer hormones? Have destinies already been affected because natural chemical messages have been disrupted by un-natural products? Apparently some scientists think so, and wonder how broad the impact has been, a difficult question because of the type of contamination, the effects over generations, and the long periods of time for effects to set in.
     “The chemical age has created products, institutions, and cultural attitudes that require synthetic chemicals to sustain them.  The task that confronts us over the next half century is one of redesign.  We must find safer ways to meet human needs.  As we work to create a future where children can be born free of chemical contamination, our scientific knowledge and technological expertise will be crucial.  Nothing, however, will be more important to human well-being and survival than the wisdom to appreciate that however great our knowledge, our ignorance is even greater.”
     I have not yet had a chance to read the whole book, just the pre-published excerpts.  I certainly do not feel the same about plastics, and heard recently that one Ontario community was banning the use of PVC-type water pipes.  If the Colborn-hypothesis is strengthened as more researchers look into this problem, I think many more such actions will have to be considered, as the above quote from Our Stolen Future shows.
     At the personal level, I was recently fitted with a plastic-type dental appliance.  I took a bad reaction to it.  (I am still tracking down exactly what it was made of.) The chemically and electromagnetically sensitive individuals in our society are the canaries and guinea pigs.  I am wondering if others are reactive to plastic materials, dental appliances, water from a plastic water jug, canned food (with plastic linings), or anything else related to plastic.